Process for treating a hydrocarbon-containing feed

ABSTRACT

A process for treating a hydrocarbon-containing feedstock is provided in which a hydrocarbon-containing feed comprising at least 20 wt. % of heavy hydrocarbons is mixed with hydrogen and at least one catalyst to produce a hydrocarbon-containing product. The hydrocarbon-containing feedstock, the catalyst(s), and the hydrogen are provided to a mixing zone and blended in the mixing zone at a temperature of from 375° C. to 500° C. A vapor comprised of hydrocarbons that are vaporizable at the temperature and pressure within the mixing zone is separated from the mixing zone, and, apart from the mixing zone, the vapor is condensed to produce a liquid hydrocarbon-containing product containing at least 85% of the atomic carbon initially present in the hydrocarbon-containing feedstock and containing at most 2 wt. % hydrocarbons having a boiling point of at least 538° C.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority from U.S.Provisional Patent Application Ser. No. 61/297,075 filed Jan. 21, 2010.

FIELD OF THE INVENTION

The present invention is directed to a process for treating ahydrocarbon-containing feedstock.

BACKGROUND OF THE INVENTION

Increasingly, resources such as heavy crude oils, bitumen, tar sands,shale oils, and hydrocarbons derived from liquefying coal are beingutilized as hydrocarbon sources due to decreasing availability of easilyaccessed light sweet crude oil reservoirs. These resources aredisadvantaged relative to light sweet crude oils, containing significantamounts of heavy hydrocarbon fractions such as residue and asphaltenes,and often containing significant amounts of sulfur, nitrogen, metals,and/or naphthenic acids. The disadvantaged crudes typically require aconsiderable amount of upgrading, for example by cracking and byhydrotreating, in order to obtain more valuable hydrocarbon products.Upgrading by cracking, either thermal cracking, hydrocracking and/orcatalytic cracking, is also effective to partially convert heavyhydrocarbon fractions such as atmospheric or vacuum residues derivedfrom refining a crude oil or hydrocarbons derived from liquefying coalinto lighter, more valuable hydrocarbons.

Numerous processes have been developed to crack and treat disadvantagedcrude oils and heavy hydrocarbon fractions to recover lighterhydrocarbons and to reduce metals, sulfur, nitrogen, and acidity of thehydrocarbon-containing material. For example, a hydrocarbon-containingfeedstock may be cracked and hydrotreated by passing thehydrocarbon-containing feedstock over a catalyst located in a fixed bedcatalyst reactor in the presence of hydrogen at a temperature effectiveto crack heavy hydrocarbons in the feedstock and/or to reduce the sulfurcontent, nitrogen content, metals content, and/or the acidity of thefeedstock. Another commonly used method to crack and/or hydrotreat ahydrocarbon-containing feedstock is to disperse a catalyst in thefeedstock and pass the feedstock and catalyst together with hydrogenthrough a slurry-bed, or fluid-bed, reactor operated at a temperatureeffective to crack heavy hydrocarbons in the feedstock and/or to reducethe sulfur content, nitrogen content, metals content, and/or the acidityof the feedstock. Examples of such slurry-bed or fluid-bed reactorsinclude ebullating-bed reactors, plug-flow reactors, and bubble-columnreactors.

Coke formation, however, is a particular problem in processes forcracking a hydrocarbon-containing feedstock having a relatively largeamount of heavy hydrocarbons such as residue and asphaltenes.Substantial amounts of coke are formed in the current processes forcracking heavy hydrocarbon-containing feedstocks, limiting the yield oflighter molecular weight hydrocarbons that can be recovered anddecreasing the efficiency of the cracking process by limiting the extentof hydrocarbon conversion that can be effected per cracking step in theprocess, for example, by deactivating the catalysts used in the process.

Cracking heavy hydrocarbons involves breaking bonds of the hydrocarbons,particularly carbon-carbon bonds, thereby forming two hydrocarbonradicals for each carbon-carbon bond that is cracked in a hydrocarbonmolecule. Numerous reaction paths are available to the crackedhydrocarbon radicals, the most important being: 1) reaction with ahydrogen donor to form a stable hydrocarbon molecule that is smaller interms of molecular weight than the original hydrocarbon from which itwas derived; and 2) reaction with another hydrocarbon or anotherhydrocarbon radical to form a hydrocarbon molecule larger in terms ofmolecular weight than the cracked hydrocarbon radical—a process calledannealation. The first reaction is desired, it produces hydrocarbons oflower molecular weight than the heavy hydrocarbons contained in thefeedstock—and preferably produces naphtha, distillate, or gas oilhydrocarbons. The second reaction is undesired and leads to theproduction of coke as the reactive hydrocarbon radical combines withanother hydrocarbon or hydrocarbon radical. Furthermore, the secondreaction is autocatalytic since the cracked hydrocarbon radicals arereactive with the growing coke particles. Hydrocarbon-containingfeedstocks having a relatively high concentration of heavy hydrocarbonmolecules therein are particularly susceptible to coking due to thepresence of a large quantity of high molecular weight hydrocarbons inthe feedstock with which cracked hydrocarbon radicals may combine toform proto-coke or coke. As a result, cracking processes of heavyhydrocarbon-containing feedstocks have been limited by coke formationinduced by the cracking reaction itself.

Processes that utilize fixed bed catalysts to crack a heavyhydrocarbon-containing material suffer significantly from catalyst agingdue to coke deposition on the catalyst over time. As noted above, cokeand proto-coke formation occurs in cracking a hydrocarbon-containingmaterial, and is particularly problematic when thehydrocarbon-containing material is a heavy hydrocarbon-containingmaterial, for example, containing at least 20 wt. % pitch, residue, orasphaltenes. The coke that is formed in the cracking process deposits onthe catalyst progressively over time, plugging the catalyst pores andcovering the surface of the catalyst. The coked catalyst loses itscatalytic activity and, ultimately, must be replaced. Furthermore, thecracking process must be conducted at relatively low crackingtemperatures to prevent rapid deactivation of the catalyst byannealation leading to coke deposition.

Slurry catalyst processes have been utilized to address the problem ofcatalyst aging by coke deposition in the course of cracking ahydrocarbon-containing feedstock. Slurry catalyst particles are selectedto be dispersible in the hydrocarbon-containing feedstock or invaporized hydrocarbon-containing feedstock so the slurry catalystscirculate with the hydrocarbon-containing feedstock in the course ofcracking the feedstock. The feedstock and the catalyst move togetherthrough the cracking reactor and are separated upon exiting the crackingreactor. Coke formed during the cracking reaction is separated from thefeedstock, and any coke deposited on the catalyst may be removed fromthe catalyst by regenerating the catalyst. The regenerated catalyst maythen be recirculated with fresh hydrocarbon-containing feedstock throughthe cracking reactor. The process, therefore, is not affected bycatalyst aging since fresh catalyst may be continually added into thecracking reactor, and catalyst upon which coke has been deposited may becontinually regenerated.

Other slurry catalysts have been used in slurry cracking processes forthe purpose of seeding the formation of coke. Very small particle slurrycatalysts may be dispersed in a hydrocarbon-containing feedstock for thepurpose of providing a plethora of small sites upon which coke maydeposit in the course of the cracking process. This inhibits theformation of large coke particles since the coke may be dispersedthroughout the hydrocarbon-containing feedstock on the small catalystparticles.

While slurry catalyst processes provide an improvement over fixed-bedcatalysis of heavy hydrocarbon feedstocks, coking remains a problem.Generally, the upper limit of recovery of hydrocarbons from a heavyhydrocarbon cracking process is around 70%, where the non-recoverablehydrocarbons are converted into coke and gas.

WO 2008/141830 and WO 2008/141831 provide a process and system forhydroconversion of heavy oils utilizing a solid accumulation reactor. Ahydrogenation catalyst is dispersed in a slurry in a reactor capable ofoperating stably in the presence of solids deriving from and generatedby a heavy oil. Heavy oil is hydroconverted to produce a lighterhydrocarbon product by reaction of the heavy oil with hydrogen and thecatalyst at temperatures effective to convert the heavy oil. Product maybe vaporized in the reactor and stripped from the slurry to be capturedas a vapor exiting the reactor, or a liquid product may be separatedfrom the reactor, where a vapor product may be separated from the liquidproduct separated from the reactor. Solids including coke and metalsproduced by the hydroconversion accumulate in the reactor and areremoved from the reactor by continuous flushing in proportion to theamount of solids generated once a pre-established minimum accumulationlevel is reached in the reactor. Large amounts of solids including coke,sulfided metals, and insoluble asphaltenes are generated in the processof producing the vapor product. As a result, the yield of desirable ofliquid hydrocarbons recovered from the heavy oil is limited by thequantity of coke and insoluble asphaltenes produced in the process.

Improved processes for cracking heavy hydrocarbon-containing feedstocksto produce a lighter hydrocarbon-containing crude product are desirable,particularly in which coke formation is significantly reduced oreliminated and the rate of hydroconversion is greatly increased.

SUMMARY OF THE INVENTION

In one aspect, the present invention is directed to a process forcracking a hydrocarbon-containing feedstock, comprising:

-   -   providing a hydrocarbon-containing feedstock to a mixing zone,        where the hydrocarbon-containing feedstock is selected to        contain at least 20 wt. % hydrocarbons having a boiling point of        greater than 538° C. as determined in accordance with ASTM        Method D5307;    -   providing a catalyst to the mixing zone;    -   continuously or intermittently providing hydrogen to the mixing        zone and blending the hydrogen, the hydrocarbon-containing        feedstock, and the catalyst in the mixing zone at a temperature        of from 375° C. to 500° C. and at a total pressure of from 6.9        MPa to 27.5 MPa to produce:        -   a) a vapor comprised of hydrocarbons that are vaporizable at            the temperature and the pressure within the mixing zone; and        -   b) a hydrocarbon-depleted feed residuum comprising            hydrocarbons that are liquid at the temperature and the            pressure within the mixing zone;    -   continuously or intermittently separating at least a portion of        the vapor from the mixing zone while retaining at least a        portion of the hydrocarbon-depleted feed residuum in the mixing        zone;

apart from the mixing zone, condensing a liquid hydrocarbon-containingproduct that

-   -   contains at least 85% of the atomic carbon initially contained        in the hydrocarbon-containing feedstock and that contains less        than 4 wt. % hydrocarbons having a boiling point of at least        538° C. as determined in accordance with ASTM Method D5307 from        at least a portion of the vapor separated from the mixing zone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a system useful for practicing the process ofthe present invention.

FIG. 2 is a schematic of a system useful for practicing the process ofthe present invention including a reactor having three zones.

FIG. 3 is a graph showing the carbon content of liquid hydrocarbonproduct, non-condensable gas, and hold-up produced by a process inaccordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a process for cracking ahydrocarbon-containing feedstock containing at least 20 wt. % heavyhydrocarbons while producing little, if any, coke, and recovering aliquid hydrocarbon-containing product that contains at least 85% of theatomic carbon present in the hydrocarbon-containing feedstock andcontains at most 4 wt. % heavy hydrocarbons. In a preferred embodimentof the process at most 0.5 wt. % coke is formed relative to the totalmass of products produced by the process.

The process of the present invention may be conducted to produce aliquid hydrocarbon product containing most of the atomic carbon from aheavy hydrocarbon-containing feedstock without containing a largequantity of heavy hydrocarbons such as pitch and without generatingsubstantial quantities of coke by-product. Although not intending thepresent invention to be limited thereby, it is believed that theproduction of coke and pitch/residue is inhibited in the process of theinvention, in part, because the metal-containing catalyst that may beutilized in the process is particularly effective at selectivelydirecting reactions occurring in the cracking process to avoid and/orinhibit coke formation, and in part, since hydrogen sulfide, whenutilized in the process, further catalyzes the cracking reactions toincrease the rate of the reactions and inhibits annealation of crackedhydrocarbons, also directing reactions occurring in the cracking andsubsequent hydrogenation to avoid and/or inhibit coke formation.

Although not intending the present invention to be limited thereby, withrespect to the metal-containing catalyst that may be utilized in theprocess, it is believed that the metal-containing catalyst is a highlyeffective catalyst for use in cracking a heavy hydrocarbon-containingmaterial without attendant production of coke, due, at least in part,to: 1) the ability of the metal-containing catalyst to donate or shareelectrons with hydrocarbons based on the molecular structure of thecatalyst (i.e. to assist in reducingreduce the hydrocarbon when thehydrocarbon is cracked so the hydrocarbon forms a hydrocarbon radicalanion); and 2) the surface area of the metal-containing catalystavailable to interact with hydrocarbons and/or hydrocarbon radicals inthe absence of any porous alumina, alumina-silica, or silica basedcarrier or support. Metal-containing catalysts that may be utilized inthe process of the present invention have little or no acidity, andpreferably are Lewis bases.

It is believed that the hydrocarbons of a hydrocarbon-containingfeedstock are cracked in the process of the present invention by a Lewisbase mediated reaction, wherein the metal-containing catalystfacilitates a reduction at the site of the hydrocarbon where thehydrocarbon is cracked, forming two hydrocarbon radical anions from aninitial hydrocarbon compound. Hydrocarbon radical anions are most stablewhen present on a primary carbon atom, therefore, formation of primaryhydrocarbon radical anions may be energetically favored when ahydrocarbon is cracked with a Lewis basic metal-containing catalyst, orthe cracked hydrocarbon may rearrange to form the more energeticallyfavored primary radical anion. Should the primary radical anion reactwith another hydrocarbon to form a larger hydrocarbon, the reaction willresult in the formation of a secondary carbon-carbon bond that issusceptible to being cracked again. However, since hydrocarbon radicalanions are relatively stable they are likely to be hydrogenated byhydrogen present in the reaction mixture rather than react with anotherhydrocarbon in an annealtion reaction, and significant hydrocarbonradical anion-hydrocarbon reactions are unlikely. As a result, littlecoke is formed by agglomeration of cracked hydrocarbons.

Conventional hydrocracking catalysts utilize an active hydrogenationmetal, for example a Group VIII metal such as nickel, on a supporthaving Lewis acid properties, for example, silica, alumina-silica, oralumina supports. The acidic support catalyzes cracking hydrocarbons andthe active hydrogenation metal catalyzes hydrogenation of the crackedhydrocarbon radicals. It is believed that cracking heavy hydrocarbons inthe presence of a catalyst having significant acidity results in theformation of cracked hydrocarbon radical cations rather than hydrocarbonradical anions. Hydrocarbon radical cations are most stable when presenton a tertiary carbon atom, therefore, cracking may be energeticallydirected to the formation of tertiary hydrocarbon radical cations, or,most likely, the cracked hydrocarbon may rearrange to form the moreenergetically favored tertiary radical cation. Hydrocarbon radicalcations are unstable relative to hydrocarbon radical anions, and mayreact rapidly with other hydrocarbons. Should the tertiary radicalcation react with another hydrocarbon to form a larger hydrocarbon, thereaction may result in the formation of a carbon-carbon bond that is notsusceptible to being cracked again. As a result, coke is formed byagglomeration of the cracked hydrocarbons in a cracking processutilizing a conventional cracking catalyst having an acidic support orcarrier.

Although the process of the invention is not to be limited thereby, itis also believed that hydrogen sulfide, when present in significantquantities, acts as a further catalyst in the cracking of hydrocarbonsin the hydrocarbon-containing feedstock. Hydrogen sulfide, insignificant quantities, inhibits the formation of coke in the process ofcracking hydrocarbons in the hydrocarbon-containing feedstock in thepresence of hydrogen and a Lewis basic metal-containing catalyst and inthe absence of a catalyst having significant acidity. It is believedthat hydrogen sulfide, in absence of significant catalytic acidity,lowers the activation energy required to crack hydrocarbons in ahydrocarbon-containing feedstock, thereby increasing the rate of thereaction. The rate of the process, in particular the rate that thehydrocarbon-containing feedstock may be provided for cracking andcracked, hydrogenated product may be produced, therefore, may be greatlyincreased with the use of significant quantities of hydrogen sulfide ina hydrocracking process. For example, the rate of the process may beincreased by at least 1.5 times, or by at least 2 times, the rate of theprocess in the absence of significant quantities of hydrogen sulfide.

Hydrogen sulfide and hydrogen each may act as a hydrogen atom donor to acracked hydrocarbon radical anion to produce a stable hydrocarbon havinga smaller molecular weight than the hydrocarbon from which thehydrocarbon radical was derived. Hydrogen, however, may only act todonate a hydrogen atom to a cracked hydrocarbon radical at or near ametal-containing catalyst surface. Hydrogen sulfide, however, may act todonate a hydrogen atom to a cracked hydrocarbon radical significantlyfurther from the metal-containing catalyst surface, and, after donationof a hydrogen atom, may accept a hydrogen atom from hydrogen near thesurface of the catalyst. The hydrogen sulfide, therefore, may act as anatomic hydrogen shuttle to provide a hydrogen atom to crackedhydrocarbon radicals at a distance from the metal-containing catalyst.

Furthermore, the thiol group remaining after hydrogen sulfide hasprovided a hydrogen atom to a cracked hydrocarbon radical may beprovided to another hydrocarbon radical, thereby forming a meta-stablethiol-containing hydrocarbon. This may be described chemically asfollows:R—C—C—R+heat+catalyst⇄R—C^(▪)+^(▪)C—R (catalyst=basic metal-containingcatalyst)  1.R—C^(▪)+H₂S⇄R—CH+^(▪)SH  2.^(▪)C—R+^(▪)SH⇄R—C—SH  3.R—C—SH+H₂⇄RCH+H₂S  4.The thiol of the meta-stable thiol-containing hydrocarbon may bereplaced by a hydrogen atom from either another hydrogen sulfidemolecule or hydrogen, or may react intramolecularly to form a thiophenecompound as a hydrocarbon-containing product.

It is believed, therefore, that hydrogen sulfide may increase the rateof the reaction 1) by lowering the activation energy of the hydrocarboncracking reaction; and 2) by facilitating the removal of crackedequilibrium products (the hydrocarbon radicals) from the equilibrium (byincreasing the rate of hydrogenation), driving the equilibrium forwardin accordance with Le Chatelier's principle; 3) providing anotherreaction path to form hydrogenated cracked hydrocarbons; and 4)permitting the use of higher reaction temperatures with concomitantproduction of coke. The hydrogen sulfide also directs the selectivity ofthe process away from producing coke by providing hydrogen at anincreased rate to the cracked hydrocarbon radicals and by providing athiol to the cracked hydrocarbon radicals—thereby inhibiting the crackedhydrocarbon radicals from agglomerating with other hydrocarbons.

Certain terms that are used herein are defined as follows:

-   “Acridinic compound” refers to a hydrocarbon compound including the    structure:

As used in the present application, an acridinic compound includes anyhydrocarbon compound containing the above structure, including,naphthenic acridines, napththenic benzoacridines, and benzoacridines, inaddition to acridine.

-   “Anaerobic conditions” means “conditions in which less than 0.5 vol.    % oxygen as a gas is present”. For example, a process that occurs    under anaerobic conditions, as used herein, is a process that occurs    in the presence of less than 0.5 vol. % oxygen in a gaseous form.    Anaerobic conditions may be such that no detectable oxygen gas is    present.-   “Aqueous” as used herein is defined as containing more than 50 vol.    % water. For example, an aqueous solution or aqueous mixture, as    used herein, contains more than 50 vol. % water.-   “ASTM” refers to American Standard Testing and Materials.-   “Atomic hydrogen percentage” and “atomic carbon percentage” of a    hydrocarbon-containing material—including crude oils, crude products    such as syncrudes, bitumen, tar sands hydrocarbons, shale oil, crude    oil atmospheric residues, crude oil vacuum residues, naphtha,    kerosene, diesel, VGO, and hydrocarbons derived from liquefying    coal—are as determined by ASTM Method D5291.-   “API Gravity” refers to API Gravity at 15.5° C., and as determined    by ASTM Method D6822.-   “Benzothiophenic compound” refers to a hydrocarbon compound    including the structure:

As used in the present application, a benzothiophenic compound includesany hydrocarbon compound containing the above structure, includingdi-benzothiophenes, naphthenic-benzothiophenes,napththenic-di-benzothiophenes, benzo-naphtho-thiophenes,naphthenic-benzo-naphthothiophenes, and dinaphtho-thiophenes, inaddition to benzothiophene.

-   “BET surface area” refers to a surface area of a material as    determined by ASTM Method D3663.-   “Blending” as used herein is defined to mean contact of two or more    substances by intimately admixing the two or more substances.-   Boiling range distributions for a hydrocarbon-containing material    may be as determined by ASTM Method D5307.-   “Bond” as used herein with reference to atoms in a molecule may    refer to a covalent bond, a dative bond, or an ionic bond, dependent    on the context.-   “Carbazolic compound” refers to a hydrocarbon compound including the    structure:

As used in the present application, a carbazolic compound includes anyhydrocarbon compound containing the above structure, includingnaphthenic carbazoles, benzocarbazoles, and napthenic benzocarbazoles,in addition to carbazole.

-   “Carbon number” refers to the total number of carbon atoms in a    molecule.-   “Catalyst” refers to a substance that increases the rate of a    chemical process and/or that modifies the selectivity of a chemical    process as between potential products of the chemical process, where    the substance is not consumed by the process. A catalyst, as used    herein, may increase the rate of a chemical process by reducing the    activation energy required to effect the chemical process.    Alternatively, a catalyst, as used herein, may increase the rate of    a chemical process by modifying the selectivity of the process    between potential products of the chemical process, which may    increase the rate of the chemical process by affecting the    equilibrium balance of the process. Further, a catalyst, as used    herein, may not increase the rate of reactivity of a chemical    process but merely may modify the selectivity of the process as    between potential products.-   “Catalyst acidity by ammonia chemisorption” refers to the acidity of    a catalyst substrate as measured by volume of ammonia adsorbed by    the catalyst substrate and subsequently desorbed from the catalyst    substrate as determined by ammonia temperature programmed desorption    between a temperature of 120° C. and 550° C. For clarity, a catalyst    that is decomposed in the measurement of acidity by ammonia    temperature programmed desorption to a temperature of 550° C. and/or    a catalyst for which a measurement of acidity may not be determined    by ammonia temperature programmed desorption, e.g. a liquid or gas,    is defined for purposes of the present invention to have an    indefinite acidity as measured by ammonia chemisorption. Ammonia    temperature programmed desorption measurement of the acidity of a    catalyst is effected by placing a catalyst sample that has not been    exposed to oxygen or moisture in a sample container such as a quartz    cell; transferring the sample container containing the sample to a    temperature programmed desorption analyzer such as a Micrometrics    TPD/TPR 2900 analyzer; in the analyzer, raising the temperature of    the sample in helium to 550° C. at a rate of 10° C. per minute;    cooling the sample in helium to 120° C.; alternately flushing the    sample with ammonia for 10 minutes and with helium for 25 minutes a    total of 3 times, and subsequently measuring the amount of ammonia    desorbed from the sample in the temperature range from 120° C. to    550° C. while raising the temperature at a rate of 10° C. per    minute.-   “Coke” is a solid carbonaceous material that is formed primarily of    a hydrocarbonaceous material and that is insoluble in toluene as    determined by ASTM Method D4072.-   “Cracking” as used herein with reference to a hydrocarbon-containing    material refers to breaking hydrocarbon molecules in the    hydrocarbon-containing material into hydrocarbon fragments, where    the hydrocarbon fragments have a lower molecular weight than the    hydrocarbon molecule from which they are derived. Cracking conducted    in the presence of a hydrogen donor may be referred to as    hydrocracking. Cracking effected by temperature in the absence of a    catalyst may be referred to a thermal cracking. Cracking may also    produce some of the effects of hydrotreating such as sulfur    reduction, metal reduction, nitrogen reduction, and reduction of    TAN.-   “Diesel” refers to hydrocarbons with a boiling range distribution    from 260° C. up to 343° C. (500° F. up to 650° F.) as determined in    accordance with ASTM Method D5307. Diesel content may be determined    by the quantity of hydrocarbons having a boiling range of from    260° C. to 343° C. relative to a total quantity of hydrocarbons as    measured by boiling range distribution in accordance with ASTM    Method D5307.-   “Dispersible” as used herein with respect to mixing a solid, such as    a salt, in a liquid is defined to mean that the components that form    the solid, upon being mixed with the liquid, are retained in the    liquid at STP for a period of at least 24 hours upon cessation of    mixing the solid with the liquid. A solid material is dispersible in    a liquid if the solid or its components are soluble in the liquid. A    solid material is also dispersible in a liquid if the solid or its    components form a colloidal dispersion or a suspension in the    liquid.-   “Distillate” or “middle distillate” refers to hydrocarbons with a    boiling range distribution from 204° C. up to 343° C. (400° F. up to    650° F.) as determined by ASTM Method D5307. Distillate may include    diesel and kerosene.-   “Hydrogen” as used herein refers to molecular hydrogen unless    specified as atomic hydrogen.-   “Insoluble” as used herein refers to a substance a majority (at    least 50 wt. %) of which does not dissolve or disperse in a liquid    after a period of 24 hours upon being mixed with the liquid at a    specified temperature and pressure, where the undissolved portion of    the substance can be recovered from the liquid by physical means.    For example, a fine particulate material dispersed in a liquid is    insoluble in the liquid if 50 wt. % or more of the material may be    recovered from the liquid by centrifugation and filtration.-   “IP” refers to the Institute of Petroleum, now the Energy Institute    of London, United Kingdom.-   “Iso-paraffins” refer to branched chain saturated hydrocarbons.-   “Kerosene” refers to hydrocarbons with a boiling range distribution    from 204° C. up to 260° C. (400° F. up to 500° F.) at a pressure of    0.101 MPa. Kerosene content may be determined by the quantity of    hydrocarbons having a boiling range of from 204° C. to 260° C. at a    pressure of 0.101 MPa relative to a total quantity of hydrocarbons    as measured by boiling range distribution in accordance with ASTM    Method D5307.-   “Lewis base” refers to a compound and/or material with the ability    to donate one or more electrons to another compound.-   “Ligand” as used herein is defined as a molecule, compound, atom, or    ion attached to, or capable of attaching to, a metal ion in a    coordination complex.-   “Light hydrocarbons” refers to hydrocarbons having a carbon number    in a range from 1 to 6.-   “Mixing” as used herein is defined as contacting two or more    substances by intermingling the two or more substances. Blending, as    used herein, is a subclass of mixing, where blending requires    intimately admixing or intimately intermingling the two or more    substances, for example into a homogenous dispersion.-   “Monomer” as used herein is defined as a molecular compound or    portion of a molecular compound that may be reactively joined with    itself or another monomer in repeated linked units to form a    polymer.-   “Naphtha” refers to hydrocarbon components with a boiling range    distribution from 38° C. up to 204° C. (100° F. up to 400° F.) at a    pressure of 0.101 MPa. Naphtha content may be determined by the    quantity of hydrocarbons having a boiling range of from 38° C. to    204° C. relative to a total quantity of hydrocarbons as measured by    boiling range distribution in accordance with ASTM Method D5307.    Content of hydrocarbon components, for example, paraffins,    iso-paraffins, olefins, naphthenes and aromatics in naphtha are as    determined by ASTM Method D6730.-   “Non-condensable gas” refers to components and/or a mixture of    components that are gases at STP.-   “n-Paraffins” refer to normal (straight chain) saturated    hydrocarbons.-   “Olefins” refer to hydrocarbon compounds with non-aromatic    carbon-carbon double bonds. Types of olefins include, but are not    limited to, cis, trans, internal, terminal, branched, and linear.-   When two or more elements are described as “operatively connected”,    the elements are defined to be directly or indirectly connected to    allow direct or indirect fluid flow between the elements.-   “Periodic Table” refers to the Periodic Table as specified by the    International Union of Pure and Applied Chemistry (IUPAC),    November 2003. As used herein, an element of the Periodic Table of    Elements may be referred to by its symbol in the Periodic Table. For    example, Cu may be used to refer to copper, Ag may be used to refer    to silver, W may be used to refer to tungsten etc.-   “Polyaromatic compounds” refer to compounds that include three or    more aromatic rings. Examples of polyaromatic compounds include, but    are not limited anthracene and phenanthrene.-   “Polymer” as used herein is defined as a compound comprised of    repetitively linked monomers.-   “Pore size distribution” refers a distribution of pore size    diameters of a material as measured by ASTM Method D4641.-   “SCFB” refers to standard cubic feet of gas per barrel of crude    feed.-   “STP” as used herein refers to Standard Temperature and Pressure,    which is 25° C. and 0.101 MPa.-   The term “soluble” as used herein refers to a substance a majority    (at least 50 wt. %) of which dissolves in a liquid upon being mixed    with the liquid at a specified temperature and pressure. For    example, a material dispersed in a liquid is soluble in the liquid    if less than 50 wt. % of the material may be recovered from the    liquid by centrifugation and filtration.-   “TAN” refers to a total acid number expressed as millgrams (“mg”) of    KOH per gram (“g”) of sample. TAN is as determined by ASTM Method    D664.-   “VGO” refers to hydrocarbons with a boiling range distribution of    from 343° C. up to 538° C. (650° F. up to 1000° F.) at 0.101 MPa.    VGO content may be determined by the quantity of hydrocarbons having    a boiling range of from 343° C. to 538° C. at a pressure of 0.101    MPa relative to a total quantity of hydrocarbons as measured by    boiling range distribution in accordance with ASTM Method D5307.-   “wppm” as used herein refers to parts per million, by weight.

The present invention is directed to a process for cracking ahydrocarbon-containing feedstock. A hydrocarbon-containing feedstockcontaining at least 20 wt. % of hydrocarbons having a boiling point ofgreater than 538° C. is selected and is provided continuously orintermittently to a mixing zone. A metal-containing catalyst is alsoprovided to the mixing zone. Hydrogen is continuously or intermittentlyprovided to the mixing zone and blended with the hydrocarbon-containingfeedstock and the catalyst(s) in the mixing zone at temperature of from375° C. to 500° C. and at a total pressure of from 6.9 MPa to 27.5 MPa(1000 psig to 4000 psig) to produce a vapor comprised of hydrocarbonsthat are vaporizable at the temperature and pressure within the mixingzone and a hydrocarbon-depleted feed residuum comprising hydrocarbonsthat are liquid at the temperature and pressure within the mixing zone.At least a portion of the vapor is separated from the mixing zone whileretaining the hydrocarbon-depleted feed residuum in the mixing zone.Apart from the mixing zone, at least a portion of the vapor separatedfrom the mixing zone is condensed to produce a liquidhydrocarbon-containing product. The liquid hydrocarbon-containingproduct contains at least 85% of the atomic carbon initially containedin the hydrocarbon-containing feedstock and contains at most 4 wt. % ofhydrocarbons having a boiling point of at least 538° C.

Hydrocarbon-Containing Feedstock

The hydrocarbon-containing feedstock contains heavy hydrocarbons thatare subject to being cracked in the process. The hydrocarbon-containingfeedstock, therefore, is selected to contain at least 20 wt. %hydrocarbons having a boiling point of greater than 538° C. asdetermined in accordance with ASTM D5307. The hydrocarbon-containingfeedstock may be selected to contain at least 25 wt. %, or at least 30wt. %, or at least 35 wt. %, or at least 40 wt. %, or at least 45 wt. %,or at least 50 wt. % hydrocarbons having a boiling point of greater than538° C. as determined in accordance with ASTM Method D5307. Thehydrocarbon-containing feedstock may be selected to contain at least 20wt. % residue, or at least 25 wt. % residue, or at least 30 wt. %residue, or at least 35 wt. % residue, or at least 40 wt. % residue, orat least 45 wt. % residue, or least 50 wt. % residue.

The hydrocarbon-containing feedstock may contain significant quantitiesof lighter hydrocarbons as well as the heavy hydrocarbons. Thehydrocarbon-containing feedstock may contain at least 30 wt. %, or atleast 35 wt. %, or at least 40 wt. %, or at least 45 wt. %, or at least50 wt. % of hydrocarbons having a boiling point of 538° C. or less asdetermined in accordance with ASTM Method D5307. Thehydrocarbon-containing feedstock may contain at least 20 wt. %, or atleast 25 wt. %, or at least 30 wt. %, or at least 35 wt. %, or at least40 wt. %, or at least 45 wt. % of naphtha and distillate hydrocarbons.The hydrocarbon-containing feedstock may be a crude oil, or may be atopped crude oil.

The hydrocarbon-containing feedstock may also contain quantities ofmetals such as vanadium and nickel. The hydrocarbon-containing feedstockmay contain at least 50 wppm vanadium and at least 20 wppm nickel.

The hydrocarbon-containing feedstock may also contain quantities ofsulfur and nitrogen. The hydrocarbon containing feedstock may contain atleast 2 wt. % sulfur, or at least 3 wt. % sulfur; and thehydrocarbon-containing feedstock may contain at least 0.25 wt. %nitrogen, or at least 0.4 wt. % nitrogen.

The hydrocarbon-containing feedstock may also contain appreciablequantities of naphthenic acids. For example, the hydrocarbon-containingfeedstock may have a TAN of at least 0.5, or at least 1.0, or at least2.0.

The process of the present invention is particularly applicable tocertain heavy petroleum and coal derived hydrocarbon-containingfeedstocks. The hydrocarbon-containing feedstock may be a heavy or anextra-heavy crude oil containing significant quantities of residue orpitch; a topped heavy or topped extra-heavy crude oil containingsignificant quantities of residue or pitch; bitumen; hydrocarbonsderived from tar sands; shale oil; crude oil atmospheric residues; crudeoil vacuum residues; asphalts; and hydrocarbons derived from liquefyingcoal.

Hydrogen

The hydrogen that is mixed with the hydrocarbon-containing feedstock andthe catalyst in the process of the present invention is derived from ahydrogen source. The hydrogen source may be hydrogen gas obtained fromany conventional sources or methods for producing hydrogen gas.Optionally, the hydrogen may provided in a synthesis gas.

Catalyst

One or more metal-containing catalysts may be utilized in the process ofthe present invention. The one or more metal-containing catalysts areselected to catalyze hydrocracking of the hydrocarbon-containingfeedstock. Each catalyst utilized in the process of the presentinvention preferably has little or no acidity to avoid catalyzing theformation of hydrocarbon radical cations and thereby avoid catalyzingthe formation of coke. Each catalyst utilized in the process of theinvention preferably has an acidity as measured by ammonia chemisorptionof at most 200, or at most 100, or at most 50, or at most 25, or at most10 μmol ammonia per gram of catalyst, and most preferably has an acidityas measured by ammonia chemisorption of 0 μmol ammonia per gram ofcatalyst. In an embodiment, the one or more catalysts comprise at most0.1 wt. %, or at most 0.01 wt. %, or at most 0.001 wt. % of alumina,alumina-silica, or silica, and, preferably, the one or more catalystscontain no detectable alumina, alumina-silica, or silica.

The one or more metal-containing catalysts used in the process of thepresent invention may contain little or no oxygen. The catalyticactivity of the metal-containing catalyst(s) in the process of thepresent invention is, in part, believed to be due to the availability ofelectrons from the catalyst(s) to stabilize cracked molecules in thecrude oil. Due to its electronegativity, oxygen tends to reduce theavailability of electrons from a catalyst when it is present in thecatalyst in appreciable quantities, therefore, each catalyst utilized inthe process preferably contains little or no oxygen. Each catalystutilized in the process may comprise at most 0.1 wt. %, or at most 0.05wt. %, or at most 0.01 wt. % oxygen as measured by neutron activation.In a preferred embodiment, oxygen is not detectable in each catalystutilized in the process.

One or more of the metal-containing catalysts may be a solid particulatesubstance having a particle size distribution with a relatively smallmean and/or median particle size, where the solid catalyst particlespreferably are nanometer size particles. A catalyst may have a particlesize distribution with a median particle size and/or mean particle sizeof at least 50 nm, or at least 75 nm, or up to 5 μm, or up to 1 μm; orup to 750 nm, or from 50 nm up to 5 μm. A solid particulate catalysthaving a particle size distribution with a large quantity of smallparticles, for example having a mean and/or median particle size of upto 5 μm, has a large aggregate surface area since little of thecatalytically active components of the catalyst are located within theinterior of a particle. A particulate catalyst having a particle sizedistribution with a large quantity of small particles, therefore, may bedesirable for use in the process of the present invention to provide arelatively high degree catalytic activity due to the surface area of thecatalyst available for catalytic activity. A catalyst used in theprocess of the invention may be a solid particulate substance preferablyhaving a particle size distribution with a mean particle size and/ormedian particle size of up to 1 μm, preferably having a pore sizedistribution with a mean pore diameter and/or a median pore diameter offrom 50 to 1000 angstroms, or from 60 to 350 angstroms, preferablyhaving a pore volume of at least 0.2 cm³/g, or at least 0.25 cm³/g or atleast 0.3 cm³/g, or at least 0.35 cm³/g, or at least 0.4 cm³/g, andpreferably having a BET surface area of at least 50 m²/g, or at least100 m²/g, and up to 400 m²/g, or up to 500 m²/g.

A solid particulate catalyst utilized in the process of the presentinvention may be insoluble in the hydrocarbon-containing feed and in thehydrocarbon-depleted feed residuum formed by the process of the presentinvention. A solid particulate catalyst having a particle sizedistribution with a median and/or mean particle size of at least 50 nmmay be insoluble in the hydrocarbon-containing feed and thehydrocarbon-depleted residuum due, in part, to the size of theparticles, which may be too large to be solvated by thehydrocarbon-containing feed or the residuum. Use of a solid particulatecatalyst which is insoluble in the hydrocarbon-containing feed and thehydrocarbon-depleted feed residuum may be desirable in the process ofthe present invention so that the catalyst may be separated from theresiduum formed by the process, and subsequently regenerated for reusein the process.

A catalyst that may be used in the process of the present invention hasan acidity as measured by ammonia chemisorption of at most 200 μmolammonia per gram of catalyst, and comprises a material comprised of ametal of Column(s) 6-10 of the Periodic Table or a compound of a metalof Column(s) 6-10 of the Periodic Table. The catalyst may be abi-metallic catalyst comprised of a metal of Column 6, 14, or 15 of thePeriodic Table or a compound of a metal of Column 6, 14, or 15 of thePeriodic Table and a metal of Column(s) 3 or 7-15 of the Periodic Tableor a compound of a metal of Column(s) 3 or 7-15 of the Periodic Table,where the catalyst has an acidity as measured by ammonia chemisorptionof at most 200 μmol ammonia per gram of catalyst.

In a preferred embodiment, a catalyst that is mixed with thehydrocarbon-containing feedstock and the hydrogen in the mixing zone iscomprised of a material that is comprised of a first metal, a secondmetal, and sulfur. The first metal of the material of the catalyst maybe a metal selected from the group consisting of copper (Cu), iron (Fe),bismuth (Bi), nickel (Ni), cobalt (Co), silver (Ag), manganese (Mn),zinc (Zn), tin (Sn), ruthenium (Ru), lanthanum (La), cerium (Ce),praseodymium (Pr), samarium (Sm), europium (Eu), ytterbium (Yb),lutetium (Lu), dysprosium (Dy), lead (Pb), and antimony (Sb). The firstmetal may be relatively electron-rich, inexpensive, and relativelynon-toxic, and preferably the first metal is selected to be copper oriron, most preferably copper. The second metal of the material of thecatalyst is a metal selected from the group consisting of molybdenum(Mo), tungsten (W), vanadium (V), tin (Sn), and antimony (Sb), where thesecond metal is not the same metal as the first metal.

The material of a preferred catalyst may be comprised of at least threelinked chain elements, where the chain elements are comprised of a firstchain element and a second chain element. The first chain elementincludes the first metal and sulfur and has a structure according toformula (I) and the second chain element includes the second metal andsulfur and has a structure according to formula (II):

where M¹ is the first metal and M² is the second metal. The catalystmaterial containing the chain elements contains at least one first chainelement and at least one second chain element. The chain elements of thematerial of the catalyst are linked by bonds between the two sulfuratoms of a chain element and the metal of an adjacent chain element. Achain element of the material of the catalyst may be linked to one, ortwo, or three, or four other chain elements, where each chain elementmay be linked to other chain elements by bonds between the two sulfuratoms of a chain element and the metal of an adjacent chain element. Atleast three linked chain elements may be sequentially linked in series.At least a portion of the material of the catalyst containing the chainelements may be comprised of the first metal and the second metal linkedby, and bonded to, sulfur atoms according to formula (III):

where M¹ is the first metal, M² is the second metal, and x is at least2. The material of the catalyst may be a polythiometallate polymer,where each monomer of the polymer is the structure as shown in formula(III) where x=1, and the polythiometallate polymer is the structure asshown in formula (III) where x is at least 5. At least a portion of thematerial of the catalyst may be comprised of the first metal and secondmetal, where the first metal is linked to the second metal by sulfuratoms as according to formula (IV) or formula (V):

where M¹ is the first metal and where M² is the second metal.

The material of the catalyst described above may comprise a third chainelement comprised of sulfur and a third metal selected from the groupconsisting of Cu, Fe, Bi, Ag, Mn, Zn, Ni, Co, Sn, Re, Rh, Pd, Ir, Pt,Ce, La, Pr, Sm, Eu, Yb, Lu, Dy, Pb, Cd, Sb, and In, where the thirdmetal is not the same as the first metal or the second metal. The thirdchain element has a structure according to formula (VI):

where M³ is the third metal. If the material of the catalyst contains athird chain element, at least a portion of the third chain element ofthe material of the catalyst is linked by bonds between the two sulfuratoms of a chain element and the metal of an adjacent chain element.

At least a portion of the catalyst material may be comprised of thefirst metal, the second metal, and sulfur having a structure accordingto formula (VII):

where M is either the first metal or the second metal, and at least oneM is the first metal and at least one M is the second metal. Thecatalyst material as shown in formula (VII) may include a third metalselected from the group consisting of Cu, Fe, Bi, Ag, Mn, Zn, Ni, Co,Sn, Re, Rh, Pd, Ir, Pt, Ce, La, Pr, Sm, Eu, Yb, Lu, Dy, Pb, Cd, Sb, andIn, where the third metal is not the same as the first metal or thesecond metal, and where M is either the first metal, or the secondmetal, or the third metal, and at least one M is the first metal, atleast one M is the second metal, and at least one M is the third metal.The portion of the catalyst material comprised of the first metal, thesecond metal, and sulfur may also have a structure according to formula(VIII):

where M is either the first metal or the second metal, at least one M isthe first metal and at least one M is the second metal, and x is atleast 2. The material of the catalyst may be a polythiometallatepolymer, where each monomer of the polymer is the structure as shown informula (VIII) where x=1, and the polythiometallate polymer is thestructure as shown in formula (VIII) where x is at least 5.

At least a portion of the material of the catalyst may be comprised ofthe first metal, the second metal, and sulfur having a structureaccording to formula (IX):

where M is either the first metal or the second metal, at least one M isthe first metal and at least one M is the second metal, and X isselected from the group consisting of SO₄, PO₄, oxalate (C₂O₄),acetylacetonate, acetate, citrate, tartrate, Cl, Br, I, ClO₄, and NO₃.For example, the material of the catalyst may contain copperthiometallate-sulfate having the structure shown in formula (X):

where n may be an integer greater than or equal to 1. The material ofthe catalyst as shown in formula (IX) may include a third metal selectedfrom the group consisting of Cu, Fe, Bi, Ag, Mn, Zn, Ni, Co, Sn, Re, Rh,Pd, Ir, Pt, Ce, La, Pr, Sm, Eu, Yb, Lu, Dy, Pb, Cd, Sb, and In, wherethe third metal is not the same as the first metal or the second metal,where M is either the first metal, or the second metal, or the thirdmetal, and at least one M is the first metal, at least one M is thesecond metal, and at least one M is the third metal. The portion of thematerial of the catalyst comprised of the first metal, the second metal,and sulfur may also have a polymeric structure according to formula(XI):

where M is either the first metal or the second metal, at least one M isthe first metal and at least one M is the second metal, X is selectedfrom the group consisting of SO₄, PO₄, oxalate (C₂O₄), acetylacetonate,acetate, citrate, tartrate, Cl, Br, I, ClO₄, and NO₃, and x is at least2 and preferably is at least 5;

At least a portion of the catalyst material may be comprised of thefirst metal, the second metal, and sulfur having a structure accordingto formula (XII):

where M is either the first metal or the second metal, at least one M isthe first metal and at least one M is the second metal, and X isselected from the group consisting of SO₄, PO₄, oxalate (C₂O₄),acetylacetonate, acetate, citrate, tartrate, Cl, Br, I, ClO₄, and NO₃.The material of the catalyst as shown in formula (XII) may include athird metal selected from the group consisting of Cu, Fe, Bi, Ag, Mn,Zn, Ni, Co, Sn, Re, Rh, Pd, Ir, Pt, Ce, La, Pr, Sm, Eu, Yb, Lu, Dy, Pb,Cd, Sb, and In, where the third metal is not the same as the first metalor the second metal, and where M is either the first metal, or thesecond metal, or the third metal, and at least one M is the first metal,at least one M is the second metal, and at least one M is the thirdmetal. The portion of the catalyst material comprised of the firstmetal, the second metal, and sulfur may also have a polymeric structureaccording to formula (XIII).

where M is either the first metal or the second metal, and at least oneM is the first metal and at least one M is the second metal, X isselected from the group consisting of SO₄, PO₄, oxalate (C₂O₄),acetylacetonate, acetate, citrate, tartrate, Cl, Br, I, ClO₄, and NO₃,and x is at least 2 and preferably is at least 5.

At least a portion of the catalyst material may be comprised of thefirst metal, the second metal, and sulfur having a structure accordingto formula (XIV):

where M is either the first metal or the second metal, at least one M isthe first metal and at least one M is the second metal, and X isselected from the group consisting of SO₄, PO₄, oxalate (C₂O₄),acetylacetonate, acetate, citrate, tartrate, Cl, Br, I, ClO₄, and NO₃.For example, at least a portion of the catalyst material may have astructure in accordance with formula (XV):

where X is selected from the group consisting of SO₄, PO₄, oxalate(C₂O₄), acetylacetonate, acetate, citrate, tartrate, Cl, Br, I, ClO₄,and NO₃, and n is an integer equal to or greater than 1. The catalystmaterial as shown in formula (XIV) may include a third metal selectedfrom the group consisting of Cu, Fe, Bi, Ag, Mn, Zn, Ni, Co, Sn, Re, Rh,Pd, Ir, Pt, Ce, La, Pr, Sm, Eu, Yb, Lu, Dy, Pb, Cd, Sb, and In, wherethe third metal is not the same as the first metal or the second metal,and where M is either the first metal, or the second metal, or the thirdmetal, and at least one M is the first metal, at least one M is thesecond metal, and at least one M is the third metal. The portion of thecatalyst material comprised of the first metal, the second metal, andsulfur may also have a polymeric structure according to formula (XVI):

where M is either the first metal or the second metal, at least one M isthe first metal and at least one M is the second metal, X is selectedfrom the group consisting of SO₄, PO₄, oxalate (C₂O₄), acetylacetonate,acetate, citrate, tartrate, Cl, Br, I, ClO₄, and NO₃, and x is at least2 and preferably is at least 5.

A preferred catalyst preferably is formed primarily of a materialcomprised of the first metal, second metal, and sulfur as describedabove, and the material of the preferred catalyst is formed primarily ofthe first metal, second metal, and sulfur as described above. The firstmetal, second metal, and sulfur may comprise at least 75 wt. %, or atleast 80 wt. %, or at least 85 wt. %, or at least 90 wt. %, or at least95 wt. %, or at least 99 wt. % or 100 wt. % of the material of thecatalyst structured as described above, where the material of thecatalyst comprises at least 50 wt. % or at least 60 wt. %, or at least70 wt. %, or at least 75 wt. %, or at least 80 wt. %, or at least 90 wt.%, or at least 95 wt. %, or at least 99 wt. % or 100 wt. % of thecatalyst.

The first metal may be present in the material of a preferred catalystdescribed above, in an atomic ratio relative to the second metal of atleast 1:2. The atomic ratio of the first metal to the second metal inthe material of the catalyst, and/or in the catalyst, may be greaterthan 1:2, or at least 2:3, or at least 1:1, or at least 2:1, or at least3:1, or at least 5:1. It is believed that the first metal contributessignificantly to the catalytic activity of the catalyst in the processof the present invention when the first metal is present in the materialof the catalyst, and/or in the catalyst, in an amount relative to thesecond metal ranging from slightly less of the first metal to the secondmetal to significantly more of the first metal to the second metal.Therefore, the first metal may be incorporated in the material of thecatalyst, and/or in the catalyst, in an amount, relative to the secondmetal, such that the atomic ratio of the first metal to the second metalranges from one half to significantly greater than one, such that thefirst metal is not merely a promoter of the second metal in thecatalyst.

A preferred catalyst—when primarily formed of the material of thecatalyst, where the material of the catalyst is primarily formed of thefirst metal, the second metal, and sulfur structured as described above,and particularly when the first metal, the second metal, and the sulfurthat form the material of the catalyst are not supported on a carrier orsupport material to form the catalyst—may have a significant degree ofporosity, pore volume, and surface area. In the absence of a support ora carrier, the catalyst may have a pore size distribution, where thepore size distribution has a mean pore diameter and/or a median porediameter of from 50 angstroms to 1000 angstroms, or from 60 angstroms to350 angstroms. In the absence of a support or a carrier, the catalystmay have a pore volume of at least 0.2 cm³/g, or at least 0.25 cm³/g, orat least 0.3 cm³/g, or at least 0.35 cm³/g, or at least 0.4 cm³/g. Inthe absence of a support or a carrier, the catalyst may have a BETsurface area of at least 50 m²/g, or at least 100 m², and up to 400 m²/gor up to 500 m²/g.

The relatively large surface area of the preferred catalyst,particularly relative to conventional non-supported bulk metalcatalysts, is believed to be due, in part, to the porosity of thecatalyst imparted by at least a portion of the material of the catalystbeing formed of abutting or adjoining linked tetrahedrally structuredatomic formations of the first metal and sulfur and the second metal andsulfur, where the tetrahedrally structured atomic formations may beedge-bonded. Interstices or holes that form the pore structure of thecatalyst may be present in the material of the catalyst as a result ofthe bonding patterns of the tetrahedral structures. Preferred catalysts,therefore, may be highly catalytically active since 1) the catalystshave a relatively large surface area; and 2) the surface area of thecatalysts is formed substantially, or entirely, of the elements thatprovide catalytic activity—the first metal, the second metal, andsulfur.

The material of a preferred catalyst may contain less than 0.5 wt. % ofligands other than sulfur-containing ligands. Ligands, other thansulfur-containing ligands, may not be present in significant quantitiesin the material since they may limit the particle size of the materialof the catalyst to less than 50 nm, for example, by inhibiting the firstmetal and the second metal from forming sulfur-bridged chains.

Method of Preparing Preferred Catalysts

A preferred metal-containing catalyst utilized in the process of thepresent invention may be prepared by mixing a first salt and a secondsalt in an aqueous mixture under anaerobic conditions at a temperatureof from 15° C. to 150° C., and separating a solid from the aqueousmixture to produce the catalyst material.

The first salt utilized to form a preferred catalyst includes a cationiccomponent comprising a metal in any non-zero oxidation state selectedfrom the group consisting of Cu, Fe, Ni, Co, Bi, Ag, Mn, Zn, Sn, Ru, La,Ce, Pr, Sm, Eu, Yb, Lu, Dy, Pb, and Sb, where the metal of the cationiccomponent is the first metal of the material of the catalyst. Thecationic component of the first salt may consist essentially of a metalselected from the group consisting of Cu, Fe, Bi, Ni, Co, Ag, Mn, Zn,Sn, Ru, La, Ce, Pr, Sm, Eu, Yb, Lu, Dy, Pb, and Sb. The cationiccomponent of the first salt must be capable of bonding with the anioniccomponent of the second salt to form the material of the catalyst in theaqueous mixture at a temperature of from 15° C. to 150° C. and underanaerobic conditions.

The first salt also contains an anionic component associated with thecationic component of the first salt to form the first salt. The anioniccomponent of the first salt may be selected from a wide range ofcounterions to the cationic component of the first salt so long as thecombined cationic component and the anionic component of the first saltform a salt that is dispersible, and preferably soluble, in the aqueousmixture in which the first salt and the second salt are mixed, and solong as the anionic component of the first salt does not prevent thecombination of the cationic component of the first salt with the anioniccomponent of the second salt in the aqueous mixture to form the materialof the catalyst. The anionic component of the first salt may be selectedfrom the group consisting of sulfate, chloride, bromide, iodide,acetate, acetylacetonate, phosphate, nitrate, perchlorate, oxalate,citrate, and tartrate.

The anionic component of the first salt may associate with or beincorporated into a polymeric structure including the cationic componentof the first salt and the anionic component of the second salt to formthe material of the catalyst. For example, the anionic component of thefirst salt may complex with a polymeric structure formed of the cationiccomponent of the first salt and the anionic component of the second saltas shown in formulas (XI) and (XIII) above, where X=the anioniccomponent of the first salt, or may be incorporated into a polymericstructure including the cationic component of the first salt and theanionic component of the second salt as shown in formula (XVI) above,where X=the anionic component of the first salt.

Certain compounds are preferred for use as the first salt to form apreferred catalyst. In particular, the first salt is preferably selectedfrom the group consisting of CuSO₄, copper acetate, copperacetylacetonate, FeSO₄, Fe₂(SO₄)₃, iron acetate, iron acetylacetonate,NiSO₄, nickel acetate, nickel acetylacetonate, CoSO₄, cobalt acetate,cobalt acetylacetonate, ZnCl₂, ZnSO₄, zinc acetate, zincacetylacetonate, silver acetate, silver acetylacetonate, SnSO₄, SnCl₄,tin acetate, tin acetylacetonate, MnSO₄, manganese acetate, manganeseacetylacetonate, bismuth acetate, bismuth acetylacetonate, and hydratesthereof. These materials are generally commercially available, or may beprepared from commercially available materials according to well-knownmethods.

The first salt is contained in an aqueous solution or an aqueousmixture, where the aqueous solution or aqueous mixture containing thefirst salt (hereinafter the “first aqueous solution”) is mixed with anaqueous solution or an aqueous mixture containing the second salt(hereinafter the “second aqueous solution”) in the aqueous mixture toform the material of the preferred catalyst. The first salt may bedispersible, and most preferably soluble, in the first aqueous solutionand is dispersible, and preferably soluble, in the aqueous mixture ofthe first and second salts. The first aqueous solution may contain morethan 50 vol. % water, or at least 75 vol. % water, or at least 90 vol. %water, or at least 95 vol. % water, and may contain more than 0 vol. %but less than 50 vol. %, or at most 25 vol. %, or at most 10 vol. %, orat most 5 vol. % of an organic solvent containing from 1 to 5 carbonsselected from the group consisting of an alcohol, a diol, an aldehyde, aketone, an amine, an amide, a furan, an ether, acetonitrile, andmixtures thereof. The organic solvent present in the first aqueoussolution, if any, should be selected so that the organic compounds inthe organic solvent do not inhibit reaction of the cationic component ofthe first salt with the anionic component of the second salt uponforming an aqueous mixture containing the first and second salts, e.g.,by forming ligands or by reacting with the first or second salts ortheir respective cationic or anionic components. The first aqueoussolution may contain no organic solvent, and may consist essentially ofwater, preferably deionized water, and the first salt.

The concentration of the first salt in the first aqueous solution may beselected to promote formation of a preferred catalyst having a particlesize distribution with a small mean and/or median particle size, wherethe particles have a relatively large surface area, upon mixing thefirst salt and the second salt in the aqueous mixture. To promote theformation of a catalyst material having a relatively large surface areaand having particle size distribution with a relatively small meanand/or median particle size, the first aqueous solution may contain atmost 3 moles per liter, or at most 2 moles per liter, or at most 1 moleper liter, or at most 0.6 moles per liter, or at most 0.2 moles perliter of the first salt.

The second salt utilized to form a preferred catalyst includes ananionic component that is a tetrathiometallate of molybdenum, vanadium,tungsten, tin or antimony. In particular, the second salt may contain ananionic component that is selected from the group consisting of MoS₄ ²⁻,WS₄ ²⁻, VS₄ ³⁻, SnS₄ ⁴⁻, and SbS₄ ³⁻.

The second salt also contains a cationic component associated with theanionic component of the second salt to form the second salt. Thecationic component of the second salt may be selected from an ammoniumcounterion, and alkali metal and alkaline earth metal counterions to thetetrathiometallate anionic component of the second salt so long as thecombined cationic component and the anionic component of the second saltform a salt that is dispersable, and preferably soluble, in the aqueousmixture in which the first salt and the second salt are mixed, and solong as the cationic component of the second salt does not prevent thecombination of the cationic component of the first salt with the anioniccomponent of the second salt in the aqueous mixture to form the catalystmaterial. The cationic component of the second salt may comprise one ormore sodium ions, or one or more potassium ions, or one or more ammoniumions.

Certain compounds are preferred for use as the second salt used to forma preferred catalyst. In particular, the second salt is preferablyselected from the group consisting of Na₂MoS₄, Na₂WS₄, Na₃VS₄, K₂MoS₄,K₂WS₄, K₃VS₄, (NH₄)₂MoS₄, (NH₄)₂WS₄, (NH₄)₃VS₄, Na₄SnS₄, (NH₄)₄SnS₄,(NH₄)₃SbS₄, Na₃SbS₄, and hydrates thereof.

The second salt may be a commercially available tetrathiomolybdate ortetrathiotungstate salt. For example, the second salt may be ammoniumtetrathiomolybdate, which is commercially available from AAA MolybdenumProducts, Inc. 7233 W. 116 Pl., Broomfield, Colo., USA 80020, ammoniumtetrathiotungstate, which is commercially available from Sigma-Aldrich,3050 Spruce St., St. Louis, Mo., USA 63103, or ammoniumtetrathiovanadate, which is commercially available from Chemos GmbH,Germany

Alternatively, the second salt may be produced from a commerciallyavailable tetrathiomolybdate or tetrathiotungstate salt. For example,the second salt may be produced from an ammonium tetrathiomolybdate,ammonium tetrathiotungstate, or ammonium tetrathiovanadate salt. Thesecond salt may be formed from the commercially available ammoniumtetrathiometallate salts by exchanging the cationic ammonium componentof the commercially available salt with a desired alkali or alkalineearth cationic component from a separate salt. The exchange of thecationic components to form the desired second salt may be effected bymixing the commercially available salt and the salt containing thedesired cationic component in an aqueous solution to form the desiredsecond salt.

A method of forming the second salt is to disperse an ammoniumtetrathiomolybdate, ammonium tetrathiotungstate, or ammoniumtetrathiovanadate in an aqueous solution, preferably water, and todisperse an alkali metal or alkaline earth metal cationic componentdonor salt, preferably a carbonate, in the aqueous solution, where thecationic component donor salt is provided in an amount relative to theammonium tetrathiomolybdate, ammonium tetrathiotungstate, or ammoniumtetrathiovanadate salt to provide a stoichiometrially equivalent orgreater amount of its cation to ammonium of the ammoniumtetrathiomolybdate, ammonium tetrathiotungstate, or ammoniumtetrathiovanadate salt. The aqueous solution may be heated to atemperature of at least 50° C., or at least 65° C. up to 100° C. toevolve ammonia from the ammonium containing salt and carbon dioxide fromthe carbonate containing salt as gases, and to form the second salt. Forexample a Na₂MoS₄ salt may be prepared for use as the second salt bymixing commercially available (NH₄)₂MoS₄ and Na₂CO₃ in water at atemperature of 70° C.-80° C. for a time period sufficient to permitevolution of a significant amount, preferably substantially all, ofammonia and carbon dioxide gases from the solution, typically from 30minutes to 4 hours, and usually about 2 hours.

If the second salt is a sodium tetrathiostannate salt, it may beproduced by dissolving Na₂Sn(OH)₆ and Na₂S in a 1:4 molar ratio inboiling deionized water (100 g of Na₂Sn(OH)₆ per 700 ml of water and 250g of Na₂S per 700 ml of water), stiffing the mixture at 90-100° C. for2-3 hours, adding finely pulverized MgO to the mixture at a 2:5 wt.ratio relative to the Na₂Sn(OH)₆ and continuing stiffing the mixture at90-100° C. for an additional 2-3 hours, cooling and collectingprecipitated impurities from the mixture, then concentrating theremaining solution by 50-60 vol. %, allowing the concentrated solutionto stand, then collecting the Na₄SnS₄ that crystallizes from theconcentrated solution. An ammonium tetrathiostannate salt may beproduced by mixing SnS₂ with (NH₄)₂S in a 1:2 mole ratio in liquidammonia under an inert gas (e.g. nitrogen), filtering, and recoveringthe solid (NH)₄SnS₄ as a residue.

The second salt is contained in an aqueous solution (the second aqueoussolution, as noted above), where the second aqueous solution containingthe second salt is mixed with the first aqueous solution containing thefirst salt in the aqueous mixture to form the preferred catalyst. Thesecond salt is preferably dispersible, and most preferably soluble, inthe second aqueous solution and is dispersible, and preferably soluble,in the aqueous mixture containing the first and second salts. The secondaqueous solution contains more than 50 vol. % water, or at least 75 vol.% water, or at least 90 vol. % water, or at least 95 vol. % water, andmay contain more than 0 vol. % but less than 50 vol. %, or at most 25vol. %, or at most 10 vol. %, or at most 5 vol. % of an organic solventcontaining from 1 to 5 carbons and selected from the group consisting ofan alcohol, a diol, an aldehyde, a ketone, an amine, an amide, a furan,an ether, acetonitrile, and mixtures thereof. The organic solventpresent in the second aqueous solution, if any, should be selected sothat the organic compounds in the organic solvent do not inhibitreaction of the cationic component of the first salt with the anioniccomponent of the second salt upon forming an aqueous mixture containingthe first and second salts, e.g., by forming ligands or by reacting withthe first or second salts or their respective cationic or anioniccomponents. Preferably, the second aqueous solution contains no organicsolvent. Most preferably the second aqueous solution consistsessentially of water, preferably deionized, and the second salt.

The concentration of the second salt in the second aqueous solution maybe selected to promote formation of a catalyst having a particle sizedistribution with a small mean and/or median particle size and having arelatively large surface area per particle upon mixing the first saltand the second salt in the aqueous mixture. To promote the formation ofa catalyst material having a particle size distribution with arelatively small mean and/or median particle size, the second aqueoussolution may contain at most 0.8 moles per liter, or at most 0.6 molesper liter, or at most 0.4 moles per liter, or at most 0.2 moles perliter, or at most 0.1 moles per liter of the second salt.

The first and second solutions containing the first and second salts,respectively, are mixed in an aqueous mixture to form the preferredcatalyst. The amount of the first salt relative to the amount of thesecond salt provided to the aqueous mixture may be selected so that theatomic ratio of the cationic component metal of the first salt to themetal of the anionic component of the second salt is at least 1:2, orgreater than 1:2, or at least 2:3, or at least 1:1, and at most 20:1, orat most 15:1, or at most 10:1.

The aqueous mixture of the first and second salts is formed by addingthe first aqueous solution containing the first salt and the secondaqueous solution containing the second salt into an aqueous solutionseparate from both the first aqueous solution and the second aqueoussolution. The separate aqueous solution will be referred hereafter asthe “third aqueous solution”. The third aqueous solution may containmore than 50 vol. % water, or at least 75 vol. % water, or at least 90vol. % water, or at least 95 vol. % water, and may contain more than 0vol. % but less than 50 vol. %, or at most 25 vol. %, or at most 10 vol.%, or at most 5 vol. % of an organic solvent containing from 1 to 5carbons and selected from the group consisting of an alcohol, a diol, analdehyde, a ketone, an amine, an amide, a furan, an ether, acetonitrile,and mixtures thereof. The organic solvent present in the third aqueoussolution, if any, should be selected so that the organic compounds inthe organic solvent do not inhibit reaction of the cationic component ofthe first salt with the anionic component of the second salt uponforming the aqueous mixture, e.g., by forming ligands or reacting withthe cationic component of the first salt or with the anionic componentof the second salt. Preferably, the third aqueous solution contains noorganic solvent, and most preferably comprises deionized water.

The aqueous mixture of the first and second salts is formed by combiningthe first aqueous solution containing the first salt and the secondaqueous solution containing the second salt in the third aqueoussolution. The volume ratio of the third aqueous solution to the firstaqueous solution containing the first salt may be from 0.5:1 to 50:1where the first aqueous solution may contain at most 3, or at most 2, orat most 1, or at most 0.8, or at most 0.5, or at most 0.3 moles of thefirst salt per liter of the first aqueous solution. Likewise, the volumeratio of the third aqueous solution to the second aqueous solutioncontaining the second salt may be from 0.5:1 to 50:1 where the secondaqueous solution may contain at most 0.8, or at most 0.4, or at most0.2, or at most 0.1 moles of the second salt per liter of the secondaqueous solution.

The first salt and the second salt may be combined in the aqueousmixture so that the aqueous mixture containing the first and secondsalts contains at most 1.5, or at most 1.2, or at most 1, or at most0.8, or at most 0.6 moles of the combined first and second salts perliter of the aqueous mixture. The particle size of the catalyst materialproduced by mixing the first and second salts in the aqueous mixtureincreases, and the surface area of the particles decreases, withincreasing concentrations of the salts. Therefore, to limit the particlesizes in the particle size distribution of the catalyst material and toincrease the relative surface area of the particles, the aqueous mixturemay contain at most 0.8 moles of the combined first and second salts perliter of the aqueous mixture, more preferably at most 0.6 moles, or atmost 0.4 moles, or at most 0.2 moles of the combined first and secondsalts per liter of the aqueous mixture. The amount of the first salt andthe total volume of the aqueous mixture may be selected to provide atmost 1, or at most 0.8, or at most 0.4 moles of the cationic componentof the first salt per liter of the aqueous mixture and the amount of thesecond salt and the total volume of the aqueous mixture may be selectedto provide at most 0.4, or at most 0.2, or at most 0.1, or at most 0.01moles of the anionic component of the second salt per liter of theaqueous mixture.

The rate of addition of the first and second aqueous solutionscontaining the first and second salts, respectively, to the aqueousmixture may be controlled to limit the instantaneous concentration ofthe first and second salts in the aqueous mixture to produce a catalystmaterial comprised of relatively small particles having relatively largesurface area. Limiting the instantaneous concentration of the salts inthe aqueous mixture may reduce the mean and/or median particle size ofthe resulting catalyst material by limiting the simultaneousavailability of large quantities of the cationic components of the firstsalt and large quantities of the anionic components of the second saltthat may interact to form a catalyst material comprised primarily ofrelatively large particles. The rate of addition of the first and secondsolutions to the aqueous mixture may be controlled to limit theinstantaneous concentration of the first salt and the second salt in theaqueous mixture to at most 0.05 moles per liter, or at most 0.01 molesper liter, or at most 0.001 moles per liter.

The first aqueous solution containing the first salt and the secondaqueous solution containing the second salt may be added to the thirdaqueous solution, preferably simultaneously, at a controlled rateselected to provide a desired instantaneous concentration of the firstsalt and the second salt in the aqueous mixture. The first aqueoussolution containing the first salt and the second aqueous solutioncontaining the second salt may be added to the third aqueous solution ata controlled rate by adding the first aqueous solution and the secondaqueous solution to the third aqueous solution in a dropwise manner. Therate that drops of the first aqueous solution and the second aqueoussolution are added to the third aqueous solution may be controlled tolimit the instantaneous concentration of the first salt and the secondsalt in the aqueous mixture as desired. The first aqueous solutioncontaining the first salt and the second aqueous solution containing thesecond salt may also be dispersed directly into the third aqueoussolution at a flow rate selected to provide a desired instantaneousconcentration of the first salt and the second salt. The first aqueoussolution and the second aqueous solution may be dispersed directly intothe third aqueous solution using conventional means for dispersing onesolution into another solution at a controlled flow rate. For example,the first aqueous solution and the second aqueous solution may bedispersed into the third aqueous solution through separate nozzleslocated within the third aqueous solution, where the flow of the firstand second solutions through the nozzles is metered by separate flowmetering devices.

The particle size distribution of the catalyst material produced bymixing the first salt and the second salt in the aqueous mixture ispreferably controlled by the rate of addition of the first and secondaqueous solutions to the third aqueous solution, as described above, sothat the median and/or mean particle size of the particle sizedistribution falls within a range of from 50 nm to 5 μm. The particlesize distribution of the catalyst material may be controlled by the rateof addition of the first and second aqueous solutions to the thirdaqueous solution so that the median and/or mean particle size of theparticle size distribution of the catalyst material may range from atleast 50 nm up to 1 μm, or up to 750 μm, or up to 500 nm.

The surface area of the catalyst material particles produced by mixingthe first and second aqueous solutions in the third aqueous solution ispreferably controlled by the rate of addition of the first and secondaqueous solutions to the third aqueous solution, as described above, sothat the BET surface area of the catalyst material particles may rangefrom 50 m²/g to 500 m²/g. The surface area of the catalyst materialparticles may be controlled by the rate of addition of the first andsecond aqueous solutions to the third aqueous solution so that the BETsurface area of the catalyst material particles is from 100 m²/g to 350m²/g

The aqueous mixture containing the first salt and the second salt ismixed to facilitate interaction and reaction of the cationic componentof the first salt with the anionic component of the second salt to formthe catalyst material. The aqueous mixture may be mixed by anyconventional means for agitating an aqueous solution or an aqueousdispersion, for example by mechanical stiffing.

During mixing of the aqueous mixture of the first and second salts, thetemperature of the aqueous mixture is maintained in the range of from15° C. to 150° C., or from 60° C. to 125° C., or from 65° C. to 100° C.When the cationic component of the second salt is ammonium, thetemperature should be maintained in a range from 65° C. to 150° C. toevolve ammonia as a gas from the second salt. The temperature of theaqueous mixture during mixing may be maintained at less than 100° C. sothat the mixing may be conducted without the application of positivepressure necessary to inhibit the water in the aqueous mixture frombecoming steam. If the second salt is a tetrathiostannate, thetemperature of the aqueous mixture may be maintained at 100° C. or lessto inhibit the degradation of the second salt into tin disulfides.

Maintaining the temperature of the aqueous mixture in a range of from50° C. to 150° C. may result in production of a catalyst material havinga relatively large surface area and a substantially reduced median ormean particle size relative to a catalyst material produced in the samemanner at a lower temperature. It is believed that maintaining thetemperature in the range of 50° C. to 150° C. drives the reaction of thecationic component of the first salt with the anionic component of thesecond salt, reducing the reaction time and limiting the time availablefor the resulting product to agglomerate prior to precipitation.Maintaining the temperature in a range of from 50° C. to 150° C. duringthe mixing of the first and second salts in the aqueous mixture mayresult in production of a catalyst material having a particle sizedistribution with a median or mean particle size of from 50 nm up to μm,or up to 1 μm, or up to 750 nm; and having a BET surface area of from 50m²/g up to 500 m²/g or from 100 m²/g to 350 m²/g.

The first and second salts in the aqueous mixture may be mixed under apressure of from 0.101 MPa to 10 MPa (1.01 bar to 100 bar). Preferably,the first and second salts in the aqueous mixture are mixed atatmospheric pressure, however, if the mixing is effected at atemperature greater than 100° C. the mixing may be conducted underpositive pressure to inhibit the formation of steam.

During mixing, the aqueous mixture of the first and second salts ismaintained under anaerobic conditions. Maintaining the aqueous mixtureunder anaerobic conditions during mixing inhibits the oxidation of thecatalyst material or the anionic component of the second salt so thatthe catalyst material produced by the process contains little, if anyoxygen other than oxygen present in the first and second salts. Theaqueous mixture of the first and second salts may be maintained underanaerobic conditions during mixing by conducting the mixing in anatmosphere containing little or no oxygen, preferably an inertatmosphere. The mixing of the first and second salts in the aqueousmixture may be conducted under nitrogen gas, argon gas, and/or steam tomaintain anaerobic conditions during the mixing. An inert gas,preferably nitrogen gas or steam, may be continuously injected into theaqueous mixture during mixing to maintain anaerobic conditions and tofacilitate mixing of the first and second salts in the aqueous mixtureand displacement of ammonia gas if the second salt contains an ammoniumcation.

The first and second salts may be mixed in the aqueous mixture at atemperature of from 15° C. to 150° C. under anaerobic conditions for aperiod of time sufficient to permit the formation of the preferredcatalyst material. The first and second salts may be mixed in theaqueous mixture for a period of at least 1 hour, or at least 2 hours, orat least 3 hours, or at least 4 hours, or from 1 hour to 10 hours, orfrom 2 hours to 9 hours, or from 3 hours to 8 hours, or from 4 hours to7 hours to form the catalyst material. The first and/or second salt(s)may be added to the aqueous mixture over a period of from 30 minutes to4 hours while mixing the aqueous mixture, and, after the entirety of thefirst and second salts have been mixed into the aqueous mixture, theaqueous mixture may be mixed for at least an additional 1 hour, or 2hours, or 3 hours or 4 hours, or 5 hours to form the catalyst material.

After completing mixing of the aqueous mixture of the first and secondsalts, a solid may be separated from the aqueous mixture to produce thepreferred catalyst material. The solid may be separated from the aqueousmixture by any conventional means for separating a solid phase materialfrom a liquid phase material. For example, the solid may be separated byallowing the solid to settle from the resulting mixture, preferably fora period of from 1 hour to 16 hours, and separating the solid from themixture by vacuum or gravitational filtration or by centrifugation. Toenhance recovery of the solid, water may be added to the aqueous mixtureprior to allowing the solid to settle. Water may be added to the aqueousmixture in a volume relative to the volume of the aqueous mixture offrom 0.1:1 to 0.75:1. Alternatively, but less preferably, the solid maybe separated from the mixture by centrifugation without first allowingthe solid to settle and/or without the addition of water. Alternatively,the aqueous mixture may be spray dried to separate the solid catalystmaterial from the aqueous mixture.

The preferred catalyst material may be washed subsequent to separationfrom the aqueous mixture, if desired. Substantial volumes of water maybe used to wash the separated catalyst material since the separatedcatalyst material is insoluble in water, and the yield of catalystmaterial will not be significantly affected by the wash.

Process for Cracking a Hydrocarbon-Containing Feedstock

In the process of the present invention, at least one metal-containingcatalyst as described above, the hydrocarbon-containing feedstock, andhydrogen are mixed, preferably blended, at a temperature of from 375° C.to 500° C. and a total pressure of 6.9 MPa to 27.5 MPa. Thehydrocarbon-containing feedstock, the catalyst(s) and hydrogen may bemixed by contact with each other in a mixing zone maintained at atemperature of from 375° C. to 500° C. and a total pressure of 6.9 MPato 27.5 MPa. Any metal-containing catalyst provided to the mixing zonemay have an acidity as measured by ammonia chemisorption of at most 200mmol ammonia per gram of catalyst. A vapor that comprises hydrocarbonsthat are a gas at the temperature and total pressure within the mixingzone is separated from the mixing zone leaving a hydrocarbon-depletedfeed residuum in the mixing zone, where the hydrocarbon-depleted feedresdiuum comprises hydrocarbons that are liquid at the temperature andpressure in the mixing zone. Apart from the mixing zone, ahydrocarbon-containing product that comprises one or more hydrocarboncompounds that are liquid at STP is condensed from the vapor separatedfrom the mixing zone. The liquid hydrocarbon-containing product containsat least 85% of the atomic carbon initially present in thehydrocarbon-containing feedstock and contains less than 4 wt. % ofhydrocarbons having a boiling point of greater than 538° C. asdetermined in accordance with ASTM Method D5307. At most 0.5 wt. % cokerelative to the total product may be formed as a by-product of theprocess.

In an embodiment of the process of the invention, as shown in FIG. 1,the mixing zone 1 may be in a reactor 3, where the conditions of thereactor 3 may be controlled to maintain the temperature and totalpressure in the mixing zone 1 at 375° C. to 500° C. and 6.9 MPa to 27.5MPa, respectively. The hydrocarbon-containing feedstock may be providedcontinuously or intermittently from a feed supply 2 to the mixing zone 1in the reactor 3 through feed inlet 5. The hydrocarbon-containingfeedstock may be preheated to a temperature of from 100° C. to 350° C.by a heating element 4, which may be a heat exchanger, prior to beingfed to the mixing zone 1.

The hydrocarbon-containing feedstock may be provided to the mixing zone1 of the reactor 3 at a rate of at least 350 kg/hr per m³ of the mixturevolume within mixing zone 1 of the reactor 3. The mixture volume isdefined herein as the combined volume of the metal-containing catalyst,the hydrocarbon-depleted feed residuum (as defined herein), and thehydrocarbon-containing feedstock in the mixing zone 1, where thehydrocarbon-depleted feed residuum may contribute no volume to themixture volume (i.e. at the start of the process before ahydrocarbon-depleted feed residuum has been produced in the mixing zone1), and where the hydrocarbon-containing feedstock may contribute novolume to the mixture volume (i.e. after initiation of the processduring a period between intermittent addition of freshhydrocarbon-containing feedstock into the mixing zone 1). The mixturevolume within the mixing zone 1 may be affected by 1) the rate ofaddition of the hydrocarbon-containing feedstock into the mixing zone 1;2) the rate of removal of the vapor from the reactor 3; and, optionally,3) the rate at which a bleed stream of the hydrocarbon-depleted feedresiduum, catalyst, and hydrocarbon-containing feedstock is separatedfrom and recycled to the reactor 3, as described in further detailbelow. The hydrocarbon-containing feedstock may be provided to themixing zone 1 of the reactor 3 at a rate of at least 400, or at least500, or at least 600, or at least 700, or at least 800, or at least 900,or at least 1000 kg/hr per m³ of the mixture volume within the mixingzone 1 up to 5000 kg/hr per m³ of the mixture volume within the mixingzone 1.

The hydrocarbon-containing feedstock may be provided to the mixing zone1 at such relatively high rates for reacting a feedstock containingrelatively large quantities of heavy, high molecular weight hydrocarbonsdue to the inhibition of coke formation in the process of the presentinvention. Conventional processes for cracking heavy hydrocarbonaceousfeedstocks are typically operated at rates on the order of 10 to 300kg/hr per m³ of reaction volume so that the conventional crackingprocess may be conducted either 1) at sufficiently low temperature toavoid excessive coke-make to maximize yield of desirable crackedhydrocarbons; or 2) at higher temperatures with significant quantitiesof coke production, where the high levels of solids produced impedesoperation of the process at a high rate.

Preferably, the mixture volume of the hydrocarbon-containing feedstock,the hydrocarbon-depleted feed residuum, and the metal-containingcatalyst is maintained within the mixing zone within a selected range ofthe reactor volume by selecting 1) the rate at which thehydrocarbon-containing feedstock is provided to the mixing zone 1;and/or 2) the rate at which a bleed stream is removed from and recycledto the mixing zone 1; and/or 3) the temperature and pressure within themixing zone 1 and the reactor 3 to provide a selected rate of vaporremoval from the mixing zone 1 and the reactor 3. The combined volume ofthe hydrocarbon-containing feedstock and the metal-containing catalystinitially provided to the mixing zone 1 at the start of the processdefine an initial mixture volume, and the amount ofhydrocarbon-containing feedstock and the amount of the catalystinitially provided to the mixing zone 1 may be selected to provide aninitial mixture volume of from 5% to 97% of the reactor volume,preferably from 30% to 75% of the reactor volume. The rate at which thehydrocarbon-containing feedstock is provided to the mixing zone 1 and/orthe rate at which a bleed stream is removed from and recycled to themixing zone 1 and/or the rate at which vapor is removed from the reactor3 and/or the temperature and total pressure within the mixing zone 1and/or the reactor 3 may be selected to maintain the mixture volume ofthe hydrocarbon-containing feedstock, the hydrocarbon-depleted feedresiduum, and the metal-containing catalyst at a level of at least 10%,or at least 25%, or at least 40%, or at least 50%, or within 70%, orwithin 50%, or from 10% to 1940%, or from 15% to 1000%, or from 20% to500%, or from 25% to 250%, or from 50% to 200% of the initial mixturevolume during the process.

Hydrogen is provided to the mixing zone 1 of the reactor 3 for mixing orblending with the hydrocarbon-containing feedstock and themetal-containing catalyst. Hydrogen may be provided continuously orintermittently to the mixing zone 1 of the reactor 3 through hydrogeninlet line 7, or, alternatively, may be mixed together with thehydrocarbon-containing feedstock, and optionally the catalyst, andprovided to the mixing zone 1 through the feed inlet 5. Hydrogen may beprovided to the mixing zone 1 of the reactor 3 at a rate sufficient tohydrogenate hydrocarbons cracked in the process. The hydrogen may beprovided to the mixing zone 1 in a ratio relative to thehydrocarbon-containing feedstock provided to the mixing zone 1 of from 1Nm³/m³ to 16,100 Nm³/m³ (5.6 SCFB to 90160 SCFB), or from 2 Nm³/m³ to8000 Nm³/m³ (11.2 SCFB to 44800 SCFB), or from 3 Nm³/m³ to 4000 Nm³/m³(16.8 SCFB to 22400 SCFB), or from 5 Nm³/m³ to 320 Nm³/m³ (28 SCFB to1792 SCFB). The hydrogen partial pressure in the mixing zone 1 may bemaintained in a pressure range of from 2.1 MPa to 27.5 MPa, or from 5MPa to 20 MPa, or from 10 MPa to 15 MPa.

The metal-containing catalyst may be located in the mixing zone 1 in thereactor 3 or may be provided to the mixing zone 1 in the reactor 3during the process of the present invention. Metal-containing catalyststhat may be utilized in the process are as described above, and excludemetal-containing catalysts exhibiting significant acidity, inparticular, catalysts having an acidity as measured by ammoniachemisorption of more than 200 μmol ammonia per gram of catalyst. Themetal-containing catalyst may be located in the mixing zone 1 in acatalyst bed. Preferably, however, the metal-containing catalyst isprovided to the mixing zone 1 during the process, or, if located in themixing zone initially, may be blended with the hydrocarbon-containingfeed and hydrogen, and is not present in a catalyst bed. Themetal-containing catalyst may be provided to the mixing zone 1 togetherwith the hydrocarbon-containing feedstock through feed inlet 5, wherethe catalyst may be dispersed in the hydrocarbon-containing feedstockprior to feeding the mixture to the mixing zone 1 through the feed inlet5. Alternatively, the metal-containing catalyst may be provided to themixing zone 1 through a catalyst inlet 9, where the catalyst may bemixed with sufficient hydrocarbon-containing feedstock or another fluid,for example a hydrocarbon-containing fluid, to enable the catalyst to bedelivered to the mixing zone 1 through the catalyst inlet 9.

The metal-containing catalyst is provided to be mixed with thehydrocarbon-containing feedstock and the hydrogen in the mixing zone 1in a sufficient amount to catalytically crack the hydrocarbon-containingfeedstock and/or to catalyze hydrogenation of the cracked hydrocarbonsin the mixing zone. An initial charge of the metal-containing catalystmay be provided for mixing with an initial charge ofhydrocarbon-containing feedstock in an amount of from 20 g to 125 g ofcatalyst per kg of initial hydrocarbon-containing feedstock. Over thecourse of the process, the metal-containing catalyst may be provided formixing with the hydrocarbon-containing feedstock and hydrogen in anamount of from 0.125 g to 5 g of catalyst per kg ofhydrocarbon-containing feedstock. Alternatively, the metal-containingcatalyst may be provided for mixing with the hydrocarbon-containingfeedstock and hydrogen over the course of the process in an amount offrom 0.125 g to 50 g of catalyst per kg of hydrocarbons in thehydrocarbon-containing feedstock having a boiling point of at least 538°C. at a pressure of 0.101 MPa.

The metal-containing catalyst, the hydrocarbon-containing feedstock, andthe hydrogen may be mixed by being blended into an intimate admixture inthe mixing zone 1. The catalyst, hydrocarbon-containing feedstock andthe hydrogen may be blended in the mixing zone 1, for example, bystirring a mixture of the components, for example by a mechanicalstirring device located in the mixing zone 1. The catalyst,hydrocarbon-containing feedstock, and hydrogen may also be mixed in themixing zone 1 by blending the components prior to providing thecomponents to the mixing zone 1 and injecting the blended componentsinto the mixing zone 1 through one or more nozzles which may act as thefeed inlet 5. The catalyst, hydrocarbon-containing feedstock, andhydrogen may also be blended in the mixing zone 1 by blending thehydrocarbon-containing feedstock and catalyst and injecting the mixtureinto the mixing zone 1 through one or more feed inlet nozzles positionedwith respect to the hydrogen inlet line 7 such that the mixture isblended with hydrogen entering the mixing zone 1 through the hydrogeninlet line 7. Baffles may be included in the reactor 3 in the mixingzone 1 to facilitate blending the hydrocarbon-containing feedstock,catalyst, and hydrogen. Less preferably, the catalyst is present in themixing zone 1 in a catalyst bed, and the hydrocarbon-containingfeedstock, hydrogen, and catalyst are mixed by bringing thehydrocarbon-containing feedstock and hydrogen simultaneously intocontact with the catalyst in the catalyst bed.

The temperature and pressure conditions in the mixing zone 1 areselected and controlled and maintained so that heavy hydrocarbons in thehydrocarbon-containing feedstock may be cracked. The temperature in themixing zone 1 is selected, controlled, and maintained from 375° C. to500° C. Preferably, the mixing zone 1 is maintained at a temperature offrom 425° C. to 500° C., or from 430° C. to 500° C., or from 440° C. to500° C., or from 450° C. to 500° C. In an embodiment of the process ofthe present invention, the temperature within the mixing zone isselected and controlled to be at least 430° C., or at least 450° C.Higher temperatures may be preferred in the process of the presentinvention since 1) the rate of conversion of the hydrocarbon-containingfeedstock to a hydrocarbon-containing product significantly increaseswith temperature; and 2) the present process inhibits or prevents theformation of coke, even at temperatures of 430° C. or greater, or 450°C. or greater, which typically occurs rapidly in conventional crackingprocesses at temperatures of 430° C. or greater, or 450° C. or greater.

Mixing the hydrocarbon-containing feedstock, the metal-containingcatalyst, and hydrogen in the mixing zone 1 at a temperature of from375° C. to 500° C. and a total pressure of from 6.9 MPa to 27.5 MPaproduces a vapor comprised of hydrocarbons that are vaporizable at thetemperature and pressure within the mixing zone 1. The vapor may becomprised of hydrocarbons present initially in thehydrocarbon-containing feedstock that vaporize at the temperature andpressure within the mixing zone 1 and hydrocarbons that are not presentinitially in the hydrocarbon-containing feedstock but are produced bycracking and hydrogenating hydrocarbons initially in thehydrocarbon-containing feedstock that were not vaporizable at thetemperature and pressure within the mixing zone 1 prior to cracking.

At least a portion of the vapor comprised of hydrocarbons that arevaporizable at the temperature and pressure within the mixing zone 1 maybe continuously or intermittently separated from the mixing zone 1containing the mixture of hydrocarbon-containing feedstock, hydrogen,and catalyst since the more volatile vapor physically separates from thehydrocarbon-containing feedstock, catalyst, and hydrogen mixture. Thevapor may also contain hydrogen gas and hydrogen sulfide gas, which alsoseparate from the mixture in the mixing zone 1.

Separation of the vapor from the mixture in the mixing zone 1 leaves ahydrocarbon-depleted feed residuum from which the hydrocarbons presentin the vapor have been removed. The hydrocarbon-depleted feed residuumis comprised of hydrocarbons that are liquid at the temperature andpressure within the mixing zone 1. The hydrocarbon-depleted feedresiduum may also be comprised of solids such as metals freed fromcracked hydrocarbons and minor amounts of coke. The hydrocarbon-depletedfeed residuum may contain little coke or proto-coke since the process ofthe present invention inhibits the generation of coke. Thehydrocarbon-depleted feed residuum may contain, per metric ton ofhydrocarbon feedstock provided to the mixing zone 1, less than 10 kg, orat most 5 kg, or at most 1 kg of hydrocarbons insoluble in toluene asmeasured by ASTM Method D4072.

At least a portion of the hydrocarbon-depleted feed residuum is retainedin the mixing zone 1 while the vapor is separated from the mixing zone1. The portion of the hydrocarbon-depleted feed residuum retained in themixing zone 1 may be subject to further cracking to produce more vaporthat may be separated from the mixing zone 1 and then from the reactor 3from which the liquid hydrocarbon-containing product may be produced bycooling. Hydrocarbon-containing feedstock and hydrogen may becontinuously or intermittently provided to the mixing zone 1 at therates described above and mixed with the metal-containing catalyst andthe hydrocarbon-depleted feed residuum retained in the mixing zone 1 toproduce further vapor comprised of hydrocarbons that are vaporizable atthe temperature and pressure within the mixing zone 1 for separationfrom the mixing zone 1 and the reactor 3.

At least a portion of the vapor separated from the mixture of thehydrocarbon-containing feedstock, hydrogen, and catalyst may becontinuously or intermittently separated from the mixing zone 1 whileretaining the hydrocarbon-depleted feed residuum, catalyst, and anyfresh hydrocarbon-containing feedstock in the mixing zone 1. At least aportion of the vapor separated from the mixing zone 1 may becontinuously or intermittently separated from the reactor 3 through areactor product outlet 11. The reactor 3 is preferably configured andoperated so that substantially only vapors and gases may exit thereactor product outlet 11, where the vapor product exiting the reactor 3comprises at most 5 wt. %, or at most 3 wt. %, or at most 1 wt. %, or atmost 0.5 wt. %, or at most 0.1 wt. %, or at most 0.01 wt. %, or at most0.001 wt. % solids and liquids at the temperature and pressure at whichthe vapor product exits the reactor 3.

A stripping gas may be injected into the reactor 3 over the mixing zone1 to facilitate separation of the vapor from the mixing zone 1. Thestripping gas may be heated to a temperature at or above the temperaturewithin the mixing zone 1 to assist in separating the vapor from themixing zone 1. In an embodiment of the process, the stripping gas may behydrogen gas and/or hydrogen sulfide gas.

As shown in FIG. 2, the reactor 3 may be comprised of a mixing zone 1, adisengagement zone 21, and a vapor/gas zone 23. The vapor comprised ofhydrocarbons that are vaporizable at the temperature and pressure withinthe mixing zone 1 may separate from the mixture of hydrocarbon-depletedresiduum, metal-containing catalyst, hydrogen, and freshhydrocarbon-containing feed, if any, in mixing zone 1 into thedisengagement zone 21. A stripping gas such as hydrogen may be injectedinto the disengagement zone 21 to facilitate separation of the vaporfrom the mixing zone 1. Some liquids and solids may be entrained by thevapor as it is separated from the mixing zone 1 into the disengagementzone 21, so that the disengagement zone 21 contains a mixture of vaporand liquids, and potentially solids. At least a portion of the vaporseparates from the disengagement zone 21 into the vapor/gas zone 23,where the vapor separating from the disengagement zone 21 into thevapor/gas zone 23 contains little or no liquids or solids at thetemperature and pressure within the vapor/gas zone. At least a portionof the vapor in the vapor/gas zone 23 exits the reactor 3 through thereactor product outlet 11.

Referring now to FIGS. 1 and 2, in the process of the present invention,the hydrocarbons in the hydrocarbon-containing feed andhydrocarbon-containing feed residuum are contacted and mixed with themetal-containing catalyst and hydrogen in the mixing zone 1 of thereactor 3 only as long as necessary to be vaporized and separated fromthe mixture, and are retained in the reactor 3 only as long as necessaryto be vaporized and exit the reactor product outlet 11. Low molecularweight hydrocarbons having a low boiling point may be vaporized almostimmediately upon being introduced into the mixing zone 1 when the mixingzone 1 is maintained at a temperature of 375° C. to 500° C. and a totalpressure of from 6.9 MPa to 27.5 MPa. These hydrocarbons may beseparated rapidly from the reactor 3. High molecular weight hydrocarbonshaving a high boiling point, for example hydrocarbons having a boilingpoint greater than 538° C. at 0.101 MPa, may remain in the mixing zone 1until they are cracked and hydrogenated into hydrocarbons having aboiling point low enough to be vaporized at the temperature and pressurein the mixing zone 1 and to exit the reactor 3. The hydrocarbons of thehydrocarbon-containing feed, therefore, are contacted and mixed with themetal-containing catalyst and hydrogen in the mixing zone 1 of thereactor 3 for a variable time period, depending on the boiling point ofthe hydrocarbons under the conditions in the mixing zone 1 and thereactor 3.

The rate of the process of producing the vapor product from thehydrocarbon-containing feedstock may be adjusted by selection of thetemperature and/or total pressure in the reactor 3, and particularly inthe mixing zone 1, within the temperature range of 375° C.-500° C. andwithin the pressure range of 6.9 MPa-27.5 MPa. Increasing thetemperature and/or decreasing the total pressure in the mixing zone 1permits the hydrocarbon-containing feedstock to provided to the reactor3 at an increased rate and the vapor product to be removed from thereactor 3 at an increased rate since the hydrocarbons in thehydrocarbon-containing feedstock may experience a decreased residencetime in the reactor 3 due to higher cracking activity and/or fastervapor removal. Conversely, decreasing the temperature and/or increasingthe total pressure in the mixing zone 1 may reduce the rate at which thehydrocarbon-containing feedstock may be provided to the reactor 3 andthe vapor product may be removed from the reactor 3 since thehydrocarbons in the hydrocarbon-containing feedstock may experience anincreased residence time in the reactor 3 due to lower cracking activityand/or slower vapor removal.

As a result of the inhibition and/or prevention of the formation of cokein the process, the hydrocarbons in the hydrocarbon-containing feed maybe contacted and mixed with the metal-containing catalyst and hydrogenin the mixing zone 1 at a temperature of 375° C. to 500° C. and a totalpressure of 6.9 MPa to 27.5 MPa for as long as necessary to bevaporized, or to be cracked, hydrogenated, and vaporized. It is believedthat high boiling, high molecular weight hydrocarbons may remain in themixing zone 1 in the presence of cracked hydrocarbons since thenon-acidic metal-containing catalyst promotes the formation ofhydrocarbon radical anions upon cracking that react with hydrogen toform stable hydrocarbon products rather than hydrocarbon radical cationsthat react with other hydrocarbons to form coke. Coke formation is alsoavoided because the cracked hydrogenated hydrocarbons preferentiallyexit the mixing zone 1 as a vapor rather remaining in the mixing zone 1to combine with hydrocarbon radicals in the mixing zone 1 to form cokeor proto-coke.

At least a portion of the vapor separated from the mixing zone 1 andseparated from the reactor 3 may be condensed apart from the mixing zone1 to produce the liquid hydrocarbon-containing product. Referring now toFIG. 1, the portion of the vapor separated from the reactor 3 may beprovided to a condenser 13 wherein at least a portion of the vaporseparated from the reactor 3 may be condensed to produce thehydrocarbon-containing product that is comprised of hydrocarbons thatare liquid at STP. A portion of the vapor separated from the reactor 3may be passed through a heat exchanger 15 to cool the vapor prior toproviding the vapor to the condenser 13.

Condensation of the liquid hydrocarbon-containing product from the vaporseparated from the reactor 3 may also produce a non-condensable gas thatmay be comprised of hydrocarbons having a carbon number from 1 to 6,hydrogen, and hydrogen sulfide. The condensed hydrocarbon-containingliquid product may be separated from the non-condensable gas through acondenser liquid product outlet 17 and stored in a product receiver 18,and the non-condensable gas may be separated from the condenser 13through a non-condensable gas outlet 19 and passed through an amine orcaustic scrubber 20 and recovered through a gas product outlet 22.

Alternatively, referring now to FIG. 2, the portion of the vaporseparated from the reactor 3 may be provided to a high pressureseparator 12 to separate a liquid hydrocarbon-containing product fromgases not condensable at the temperature and pressure within the highpressure separator 12, and the liquid hydrocarbon-containing productcollected from the high pressure separator may be provided through line16 to a low pressure separator 14 operated at a pressure less than thehigh pressure separator 12 to separate the liquid hydrocarbon-containingproduct from gases that are not condensable at the temperature andpressure at which the low pressure separator 14 is operated. Thevapor/gas exiting the reactor 3 from the reactor product outlet 11 maybe cooled prior to being provided to the high pressure separator 12 bypassing the vapor/gas through heat exchanger 15. The condensedhydrocarbon-containing liquid product may be separated from thenon-condensable gas in the low pressure separator through a low pressureseparator liquid product outlet 10 and stored in a product receiver 18.The non-condensable gas may be separated from the high pressureseparator 12 through a high pressure non-condensable gas outlet 24 andfrom the low pressure separator 14 through a low pressurenon-condensable gas outlet 26. The non-condensable gas streams may becombined in line 28 and passed through an amine or caustic scrubber 20and recovered through a gas product outlet 22.

A portion of the hydrocarbon-depleted feed residuum and metal-containingcatalyst may be separated from the mixing zone to remove solidsincluding metals and hydrocarbonaceous solids including coke from thehydrocarbon-depleted feed residuum Referring now to FIGS. 1 and 2, thereactor 3 may include a bleed stream outlet 25 for removal of a streamof hydrocarbon-depleted feed residuum and catalyst from the mixing zone1 and the reactor 3. The bleed stream outlet 25 may be operativelyconnected to the mixing zone 1 of the reactor 3.

A portion of the hydrocarbon-depleted feed residuum and the catalyst maybe removed together from the mixing zone 1 and the reactor 3 through thebleed stream outlet 25 while the process is proceeding. Solids and thecatalyst may be separated from a liquid portion of thehydrocarbon-depleted feed residuum in a solid-liquid separator 30. Thesolid-liquid separator 30 may be a filter or a centrifuge. The liquidportion of the hydrocarbon-depleted feed residuum may be recycled backinto the mixing zone 1 via a recycle inlet 32 for further processing ormay be combined with the hydrocarbon-containing feed and recycled intothe mixing zone 1 through the feed inlet 5.

In a preferred embodiment, hydrogen sulfide is mixed, and preferablyblended, with the hydrocarbon-containing feedstock, hydrogen, anyhydrocarbon-depleted feed residuum, and the metal-containing catalyst inthe mixing zone 1 of the reactor 3. The hydrogen sulfide may be providedcontinuously or intermittently to the mixing zone 1 of the reactor 3 asa liquid or a gas. The hydrogen sulfide may be mixed with thehydrocarbon-containing feedstock and provided to the mixing zone 1 withthe hydrocarbon-containing feedstock through the feed inlet 5.Alternatively, the hydrogen sulfide may be mixed with hydrogen andprovided to the mixing zone 1 through the hydrogen inlet line 7.Alternatively, the hydrogen sulfide may be provided to the mixing zone 1through a hydrogen sulfide inlet line 27.

As discussed above, it is believed that hydrogen sulfide acts as afurther catalyst in cracking hydrocarbons in the hydrocarbon-containingfeedstock in the presence of hydrogen and the catalyst and lowers theactivation energy to crack hydrocarbons in the hydrocarbon-containingfeed stock, thereby increasing the rate of the reaction. The rate of theprocess, in particular the rate that the hydrocarbon-containingfeedstock may be provided to the mixing zone 1 for cracking and crackedproduct may be removed from the reactor 3, therefore, may be greatlyincreased with the use of significant quantities of hydrogen sulfide inthe process. For example, the rate of the process may be increased by atleast 1.5 times, or by at least 2 times, the rate of the process in theabsence of significant quantities of hydrogen sulfide.

It is also believed that the hydrogen sulfide inhibits coke formationunder cracking conditions. Use of sufficient hydrogen sulfide in theprocess permits the process to be effected at a mixing zone temperatureof at least at least 430° C. or at least 450° C. with little or noincrease in coke formation relative to cracking conducted at lowertemperatures since hydrogen sulfide inhibits coke formation. The rate ofthe process, in particular the rate that the hydrocarbon-containingfeedstock may be provided to the mixing zone 1 for cracking and crackedhydrogenated product may be removed from the reactor 3, therefore, maybe greatly increased with the use of significant quantities of hydrogensulfide in the process since the rate of reaction in the processincreases significantly relative to temperature, and the reaction may beconducted at higher temperatures in the presence of hydrogen sulfidewithout significant coke production.

Hydrogen sulfide may be provided to be mixed with thehydrocarbon-containing feedstock, the hydrocarbon-depleted residuum, thecatalyst(s), and hydrogen in an amount effective to inhibit theformation of coke in the process. The hydrogen sulfide provided to bemixed with the hydrocarbon-containing feedstock, hydrogen, and thecatalyst may also be provided in an amount effective to increase therate of the cracking reaction. In order to increase the rate of thecracking reaction and/or to inhibit coke formation, hydrogen sulfide maybe provided in an amount on a mole ratio basis relative to hydrogenprovided to be mixed with the hydrocarbon-containing feedstock andcatalyst, of at least 0.5 mole of hydrogen sulfide per 9.5 moleshydrogen, where the combined hydrogen sulfide and hydrogen partialpressures are maintained to provide at least 60%, or at least 70%, or atleast 80%, or at least 90%, or at least 95% of the total pressure in thereactor. The hydrogen sulfide may be provided to the mixing zone 1 in anamount on a mole ratio basis relative to the hydrogen provided to themixing zone 1 of at least 1:9, or at least 1.5:8.5, or at least 2.5:7.5,or at least 3:7 or at least 3.5:6.5, or at least 4:6, up to 1:1, wherethe combined hydrogen sulfide and hydrogen partial pressures aremaintained to provide at least 60%, or at least 70%, or at least 80%, orat least 90%, or at least 95% of the total pressure in the reactor. Thehydrogen sulfide partial pressure in the reactor may be maintained in apressure range of from 0.4 MPa to 13.8 MPa, or from 2 MPa to 10 MPa, orfrom 3 MPa to 7 MPa.

The combined partial pressure of the hydrogen sulfide and hydrogen inthe reactor may be maintained to provide at least 60% of the totalpressure in the reactor, where the hydrogen sulfide partial pressure ismaintained at a level of at least 5% of the hydrogen partial pressure.Preferably, the combined partial pressure of the hydrogen sulfide andhydrogen in the reactor is maintained to provide at least 70%, or atleast 75%, or at least 80%, or at least 90%, or at least 95% of thetotal pressure in the reactor, where the hydrogen sulfide partialpressure is maintained at a level of at least 5% of the hydrogen partialpressure. Other gases may be present in the reactor in minor amountsthat provide a pressure contributing to the total pressure in thereactor. For example, a non-condensable gas produced in the vapor alongwith the hydrocarbon-containing product may be separated from thehydrocarbon-containing product and recycled back into the mixing zone,where the non-condensable gas may comprise hydrocarbon gases such asmethane, ethane, and propane as well as hydrogen sulfide and hydrogen.

The vapor separated from the mixing zone 1 and from the reactor 3through the reactor product outlet 11 may contain hydrogen sulfide. Thehydrogen sulfide in the vapor product may be separated from thehydrocarbon-containing liquid product in the condenser 13 (FIG. 1) or inthe high and low pressure separators 12 and 14 (FIG. 2), where thehydrogen sulfide may form a portion of the non-condensable gas. Whenhydrogen sulfide is provided to the mixing zone 1 in the process, it ispreferable to condense the hydrocarbon-containing liquid product at atemperature of from 60° C. to 93° C. (140° F.-200° F.) so that hydrogensulfide is separated from the hydrocarbon-containing liquid product withthe non-condensable gas rather than condensing with the liquidhydrocarbon-containing product. The non-condensable gas including thehydrogen sulfide may be recovered from the condenser 13 through the gasproduct outlet 19 (FIG. 1) or from the high pressure separator 12through high pressure separator gas outlet 24 and the low pressureseparator gas outlet 26 (FIG. 2).

The hydrogen sulfide may be separated from the other components of thenon-condensable gas by treatment of the non-condensable gas to recoverthe hydrogen sulfide. For example, the non-condensable gas may bescrubbed with an amine solution in the scrubber 20 to separate thehydrogen sulfide from the other components of the non-condensable gas.The hydrogen sulfide may then be recovered and recycled back into themixing zone 1.

The process of the present invention may be effected for a substantialperiod of time on a continuous or semi-continuous basis, in part becausethe process generates little or no coke. The hydrocarbon-containingfeedstock, hydrogen, metal-containing catalyst, and hydrogen sulfide (ifused in the process) may be continuously or intermittently provided tothe mixing zone 1 in the reactor 3, preferably where thehydrocarbon-containing feedstock is provided at a rate of at least 350kg/hr per m³ of the mixture volume as defined above, and mixed in themixing zone 1 at a temperature of from 375° C.-500° C. and a totalpressure of from 6.9 MPa-27.5 MPa for a period of at least 40 hours, orat least 100 hours, or at least 250 hours, or at least 500 hours, or atleast 750 hours to generate the vapor comprised of hydrocarbons that arevaporizable at the temperature and pressure in the mixing zone 1 and thehydrocarbon-depleted feed residuum, as described above. The vapor may becontinuously or intermittently separated from the mixing zone 1 and thereactor 3 and subsequently condensed apart from the mixing zone 1 oversubstantially all of the time period that the hydrocarbon-containingfeedstock, catalyst, hydrogen, and hydrogen sulfide, if any, are mixedin the mixing zone 1. Fresh hydrocarbon-containing feedstock, hydrogen,and hydrogen sulfide, if used in the process, may be blended with thehydrocarbon-depleted feed residuum and catalyst in the mixing zone 1over the course of the time period of the reaction as needed. In apreferred embodiment, fresh hydrocarbon-containing feedstock, hydrogen,and hydrogen sulfide, if any, are provided continuously to the mixingzone 1 over substantially all of the time period the reaction iseffected. Solids may be removed from the mixing zone 1 continuously orintermittently over the time period the process is run by separating ableed stream of the hydrocarbon-containing feed residuum from the mixingzone 1 and the reactor 3, removing the solids from the bleed stream, andrecycling the bleed stream from which the solids have been removed backinto the mixing zone 1 as described above.

The process of the present invention produces, in part, ahydrocarbon-containing product that is a liquid at STP. Thehydrocarbon-containing product may contain less than 4 wt. %, or lessthan 3 wt. %, or at most 2 wt. %, or at most 1 wt. %, or at most 0.5 wt.% of hydrocarbons having a boiling point of greater than 538° C. asdetermined in accordance with ASTM Method D5307. Furthermore, thehydrocarbon-containing product may contain at least 85%, or at least90%, or at least 95%, or at least 97% of the atomic carbon present inthe hydrocarbon-containing feedstock. Very little coke by-product isproduced in the process of the present invention where at most 0.5 wt.%, or at most 0.25 wt. %, or at most 0.1 wt. % coke is produced relativeto the total product as determined in accordance with ASTM Method D4072.A relatively small amount of the total product is produced asnon-condensable hydrocarbon gas, typically at most 5 wt. %, or at most 3wt. %. Therefore, when the process of the present invention is utilized,most of the hydrocarbons in the hydrocarbon-containing feedstock may berecovered in the hydrocarbon-containing product that is liquid at STP,and little of the hydrocarbons in the hydrocarbon-containing feedstockare converted to coke or non-condensable gas.

The liquid hydrocarbon-containing product may contain VGO hydrocarbons,distillate hydrocarbons, and naphtha hydrocarbons. The liquidhydrocarbon-containing product may contain, per gram, at least 0.05grams, or at least 0.1 grams of hydrocarbons having a boiling point fromthe initial boiling point of the hydrocarbon-containing product up to204° C. (400° F.). The liquid hydrocarbon-containing product may alsocontain, per gram, at least 0.1 grams, or at least 0.15 grams ofhydrocarbons having a boiling point of from 204° C. (400° F.) up to 260°C. (500° F.). The liquid hydrocarbon-containing product may alsocontain, per gram, at least 0.25 grams, or at least 0.3 grams, or atleast 0.35 grams of hydrocarbons having a boiling point of from 260° C.(500° F.) up to 343° C. (650° F.). The liquid hydrocarbon-containingproduct may also contain, per gram, at least 0.3 grams, or at least 0.35grams, or at least 0.4, or at least 0.45 grams of hydrocarbons having aboiling point of from 343° C. (500° F.) up to 538° C. (1000° F.). Therelative amounts of hydrocarbons within each boiling range and theboiling range distribution of the hydrocarbons may be determined inaccordance with ASTM Method D5307.

The liquid hydrocarbon-containing product produced by the process of thepresent invention may contain significant amounts of sulfur. The liquidhydrocarbon-containing product may contain, per gram, at least 0.0005gram of sulfur or at least 0.001 gram of sulfur. The sulfur content ofthe liquid hydrocarbon-containing product may be determined inaccordance with ASTM Method D4294. In the liquid hydrocarbon-containingproduct, at least 40 wt. % of the sulfur may be contained in hydrocarboncompounds having a carbon number of 17 or less as determined bytwo-dimensional GC-GC sulfur chemiluminescence, where at least 60 wt. %of the sulfur in the sulfur-containing hydrocarbon compounds having acarbon number of 17 or less may be contained in benzothiopheniccompounds as determined by GC-GC sulfur chemiluminescence.

-   -   The hydrocarbon-containing product produced by the process of        the present invention may contain, per gram, at least 0.0005        gram or at least 0.001 gram of nitrogen as determined in        accordance with ASTM Method D5762. The hydrocarbon-containing        product may have a relatively low ratio of basic nitrogen        compounds to other nitrogen containing compounds therein. The        nitrogen may be contained in hydrocarbon compounds, where at        least 30 wt. % of the nitrogen in the liquid        hydrocarbon-containing product may be contained in        nitrogen-containing hydrocarbon compounds having a carbon number        of 17 or less and where at least 50 wt. % of the        nitrogen-containing hydrocarbon compounds having a carbon number        of 17 or less are acridinic and carbazolic compounds. The amount        of nitrogen-containing hydrocarbon compounds having a carbon        number of 17 or less relative to the amount of nitrogen in all        nitrogen-containing hydrocarbon compounds in the liquid        hydrocarbon-containing product and the relative amount of        acridinic and carbazolic compounds may be determined by nitrogen        chemiluminescence two dimensional gas chromatography        (GC×GC-NCD).

The hydrocarbon-containing product produced by the process of thepresent invention may contain significant quantities of aromatichydrocarbon compounds. The hydrocarbon-containing product may contain,per gram, at least 0.3 gram, or at least 0.35 gram, or at least 0.4gram, or at least 0.45 gram, or at least 0.5 gram of aromatichydrocarbon compounds.

The hydrocarbon-containing product of the process of the presentinvention may contain relatively few polyaromatic hydrocarbon compoundscontaining three or more aromatic ring structures (e.g. anthracene,phenanthrene) relative to mono-aromatic and di-aromatic hydrocarboncompounds. The combined mono-aromatic and di-aromatic hydrocarboncompounds in the hydrocarbon-containing product may be present in thehydrocarbon-containing product in a weight ratio relative to thepolyaromatic hydrocarbon compounds (containing three or more aromaticring structures) of at least 1.5:1.0, or at least 2.0:1.0, or at least2.5:1.0. The relative amounts of mono-aromatic, di-aromatic, andpolyaromatic compounds in the hydrocarbon-containing product may bedetermined by flame ionization detection-two dimensional gaschromatography (GC×GC-FID).

To facilitate a better understanding of the present invention, thefollowing examples of certain aspects of some embodiments are given. Inno way should the following examples be read to limit, or define, thescope of the invention.

EXAMPLE 1

A catalyst for use in a process of the present invention containingcopper, molybdenum, and sulfur was produced, where at least a portion ofthe catalyst had a structure according to Formula (XVII):

A solution was prepared by mixing 781 grams of ammoniumtetrathiomolybdate and 636 grams of Na₂CO₃ in 6 liters of deionizedwater. The solution was heated to 70° C. with stirring to generateNa₂MoS₄. The Na₂MoS₄ solution was then allowed to cool overnight. Aseparate solution of CuSO₄ was prepared by mixing 1498 grams of CuSO₄ in6 liters of water. The CuSO₄ solution was then added to the Na₂MoS₄solution via pneumatic pump through a 0.02″×0.5″ nozzle while stiffingthe mixture at ambient temperature. The mixture was stirred for twohours, and then the resulting solids were separated by centrifuge. 880grams of solid particulate catalyst was recovered. The solids were thenwashed with water until the effluent from the wash had a conductivity of488 μS at 33° C. The catalyst solids were particulate and had a particlesize distribution with a mean particle size of 8.5 μm as determined bylaser diffractometry using a Mastersizer S (Malvern Instruments). TheBET surface area of the catalyst solids was measured to be 29.3 m²/g.Semi-quantitative XRF of the catalyst solids indicated that the catalystsolids contained 45.867 mass % Cu, 18.587 mass % Mo, and 27.527 mass %S. X-ray diffraction and Raman IR spectroscopy confirmed that at least aportion of the catalyst had a structure in which copper, molybdenum, andsulfur were arranged as shown in formula (XVII) above.

EXAMPLE 2

Peace River bitumen having the composition shown in Table 1 washydrocracked in a process in accordance with the present inventionutilizing the catalyst prepared in Example 1 to determine the relativeamounts of liquid hydrocarbon product, non-compressible gas, and cokeproduced by the hydrocracking reaction.

TABLE 1 Property Value Hydrogen (wt. %) 10.1 Carbon (wt. %) 82 Oxygen(wt. %) 0.62 Nitrogen (wt. %) 0.37 Sulfur (wt. %) 6.69 Nickel (wppm) 70Vanadium (wppm) 205 Microcarbon residue (wt. %) 12.5 C5 asphaltenes (wt.%) 10.9 Density (g/ml) 1.01 Viscosity at 38° C. (cSt) 8357 TAN-E (ASTMD664) (mg KOH/g) 3.91 Boiling Range Distribution Initial BoilingPoint-204° C. (400° F.) (wt. %) [Naphtha] 0   204° C. (400° F.)-260° C.(500° F.) (wt. %) [Kerosene] 1   260° C. (500° F.)-343° C. (650° F.)(wt. %) [Diesel] 14   343° C. (650° F.)-538° C. (1000° F.) (wt. %) [VGO]37.5 >538° C. (1000° F.) (wt. %) [Residue] 47.5

Three samples of the Peace River bitumen were hydrocracked at differenthydrogen and hydrogen sulfide levels utilizing the catalyst prepared inExample 1. Hydrogen sulfide was provided at 0 mol %, 11.4 mol %, and20.1 mol % of the gas fed to the reactor in each respectivehydrocracking treatment. Hydrogen was provided at 68.6 mol % of the gasfed to the reactor when hydrogen sulfide was provided at 11.4 mol %(mole ratio of 1:6, hydrogen sulfide:hydrogen); at 69.9 mol % of the gasfed to the reactor when hydrogen sulfide was provided at 20.1 mol %(mole ratio of 1:3.5, hydrogen sulfide:hydrogen) and at 70.2 mol % when0 mol % hydrogen sulfide was used. Nitrogen was provided as an inert gasin the gas fed to the reactor to maintain the total pressure of thereaction at 8.3 MPa, where nitrogen was provided as 20 mol % of the gasfed to the reactor when hydrogen sulfide was provided at 11.4 mol % ofthe gas fed to the reactor; as 10 mol % of the gas fed to the reactorwhen hydrogen sulfide was provided at 20.1 mol % of the gas fed to thereactor; and as 29.8 mol % of the gas fed to the reactor when nohydrogen sulfide was fed to the reactor. Hydrogen and hydrogen sulfideprovided 80% of the total pressure when hydrogen sulfide was provided at11.4 mol % and 20.1 mol % of the gas fed to the reactor, and hydrogenprovided 70.2% of the total pressure when only hydrogen and nitrogenwere fed to the reactor. The combined hydrogen, hydrogen sulfide, andnitrogen were fed to the reactor as a gas flow rate of 900 standardliters per hour for each hydrocracking treatment, and the total pressurewas maintained at 8.3 MPa.

In each hydrocracking treatment, the bitumen was preheated toapproximately 105° C.-115° C. in a 10 gallon feed drum and circulatedthrough a closed feed loop system from which the bitumen was fed into asemi-continuous stirred tank reactor with vapor effluent capability,where the reactor had an internal volume capacity of 1000 cm³. Thereactor was operated in a continuous mode with respect to the bitumenfeedstream and the vapor effluent product, however, the reactor did notinclude a bleed stream to remove accumulating metals and/or carbonaceoussolids. The bitumen feed of each sample was fed to the reactor as neededto maintain a working volume of feed in the reactor of 500 ml as vaporeffluent exited the reactor, therefore, the liquid hourly space velocityof the bitumen feed depended on the rate of the reaction. A Bertholdsingle-point source nuclear level detector located outside the reactorwas used to control the working volume in the reactor. 50 grams of thecatalyst was mixed with the hydrogen, hydrogen sulfide, and bitumen feedsample in the reactor in each hydrocracking treatment. The bitumen feedsample, hydrogen, hydrogen sulfide, and the catalyst were mixed togetherat in the reactor by stirring with an Autoclave Engineers MagneDrive®impeller at 1200 rpm. The temperature of the reaction was maintained at420° C. Vaporized product exited the reactor, where a liquid product wasseparated from the vaporized product by passing the vaporized productthrough a high pressure separator operated at reaction pressure and 80°C. and then through a low pressure separator operated at 1.38 MPa and80° C. to condense and separate the liquid product from non-condensablegases.

The yield of liquid hydrocarbon product, non-condensable gas—includinghydrogen, hydrogen sulfide, and hydrocarbons having a carbon number offrom 1 to 6, and hold-up were measured and compared with the carboncontent of the feed provided. Hold-up included residual high molecularweight hydrocarbons that did not vaporize as product and metals. Theresults are shown in Table 1 and FIG. 1.

TABLE 1 Sample 1 Sample 2 Sample 3 0 mol % H₂S 11.4 mol % H₂S 20 mol %H₂S Liquid 85.1 85.0 88.6 Hydrocarbon Non-Condensable 11.0 16.3 12.9 gasHold-up 3.1 2.4 2.3 Carbon closure 99.3 103.7 103.8 (in/out)

As shown in Table 1, at least 85% of the carbon content of the materialproduced by the hydrocracking reaction was captured as liquidhydrocarbon product.

The liquid hydrocarbon product of each sample was then measured todetermine the amount of naphtha, distillate, vacuum gas oil (VGO), andpitch contained in the liquid hydrocarbon product. In this example,naphtha content contained hydrocarbons having a boiling range from theinitial boiling point of the sample to 180° C.; distillate contentcontained hydrocarbons having a boiling point range from 180° C. to 360°C.; VGO content contained hydrocarbons having a boiling point range from360° C. to 538° C.; and pitch content contained hydrocarbons having aboiling point above 538° C. The results are shown in Table 2.

TABLE 2 Sample 1 Sample 2 Sample 3 (0 mol % H₂S) (11.4 mol % H₂S) (20.1mol % H₂S) Naphtha 11.3 10.9 12.3 Distillate 35.6 37.1 37.0 VGO 51.450.3 49.0 Pitch 1.7 1.7 1.7

As shown in Table 2, the liquid hydrocarbon products produced by eachhydrocracking treatment contained only 1.7 wt. % of hydrocarbons havinga boiling point of greater than 538° C. (pitch).

The present invention is well adapted to attain the ends and advantagesmentioned as well as those that are inherent therein. The particularembodiments disclosed above are illustrative only, as the presentinvention may be modified and practiced in different but equivalentmanners apparent to those skilled in the art having the benefit of theteachings herein. Furthermore, no limitations are intended to thedetails of construction or design herein shown, other than as describedin the claims below. It is therefore evident that the particularillustrative embodiments disclosed above may be altered or modified andall such variations are considered within the scope and spirit of thepresent invention. While compositions and methods are described in termsof “comprising,” “containing,” or “including” various components orsteps, the compositions and methods can also “consist essentially of” or“consist of” the various components and steps. Whenever a numericalrange with a lower limit and an upper limit is disclosed, any number andany included range falling within the range is specifically disclosed.In particular, every range of values (of the form, “from a to b,” or,equivalently, “from a-b”) disclosed herein is to be understood to setforth every number and range encompassed within the broader range ofvalues. Whenever a numerical range having a specific lower limit only, aspecific upper limit only, or a specific upper limit and a specificlower limit is disclosed, the range also includes any numerical value“about” the specified lower limit and/or the specified upper limit Also,the terms in the claims have their plain, ordinary meaning unlessotherwise explicitly and clearly defined by the patentee. Moreover, theindefinite articles “a” or “an”, as used in the claims, are definedherein to mean one or more than one of the element that it introduces.

We claim:
 1. A process for cracking a hydrocarbon-containing feedstock,comprising: providing a hydrocarbon-containing feedstock to a mixingzone, where the hydrocarbon-containing feedstock is selected to containat least 20 wt. % hydrocarbons having a boiling point of greater than538° C. as determined in accordance with ASTM Method D5307; providing acatalyst to the mixing zone; continuously or intermittently providinghydrogen to the mixing zone and blending the hydrogen, thehydrocarbon-containing feedstock, and the catalyst in the mixing zone ata temperature of from 375° C. to 500° C. and at a total pressure of from6.9 MPa to 27.5 MPa to produce: a) a vapor comprised of hydrocarbonsthat are vaporizable at the temperature and the pressure within themixing zone; and b) a hydrocarbon-depleted feed residuum comprisinghydrocarbons that are liquid at the temperature and the pressure withinthe mixing zone; continuously or intermittently separating at least aportion of the vapor from the mixing zone while retaining at least aportion of the hydrocarbon-depleted feed residuum in the mixing zone;apart from the mixing zone, condensing a liquid hydrocarbon-containingproduct that contains at least 90% of the atomic carbon initiallycontained in the hydrocarbon-containing feedstock and that contains lessthan 2 wt. % hydrocarbons having a boiling point of greater than 538° C.as determined in accordance with ASTM Method D5307 from at least aportion of the vapor separated from the mixing zone.
 2. The process ofclaim 1 wherein the hydrocarbon-containing feedstock is continuously orintermittently provided to the mixing zone.
 3. The process of claim 2wherein the combined volume of the hydrocarbon-depleted feed residuum,the catalyst, and the hydrocarbon-containing feedstock in the mixingzone defines a mixture volume, and wherein the hydrocarbon-containingfeedstock is provided to the mixing zone at a flow rate of at least 350kg/hr per m³ of the mixture volume in the mixing zone.
 4. The process ofclaim 2 wherein: the mixing zone is located in a reactor; the reactorhas a reactor volume; the hydrocarbon-containing feedstock and thecatalyst initially provided to the mixing zone define an initial mixturevolume, where the initial mixture volume is from 5% to 97% of thereactor volume; and where the mixture volume of the catalyst, thehydrocarbon-containing feedstock, and the hydrocarbon-depleted feedresiduum is maintained at a level of from 10% to 1940% of the initialmixture volume.
 5. The process of claim 4 wherein the vapor separatedfrom the mixing zone is separated from the reactor.
 6. The process ofclaim 1 wherein the hydrocarbon-depleted feed residuum is blended withhydrogen and the catalyst in the mixing zone while separating at least aportion of the vapor from the mixing zone.
 7. The process of claim 1wherein the liquid hydrocarbon-containing product condensed from theportion of the vapor separated from the mixing zone contains less than 1wt. % hydrocarbons having a boiling point of greater than 538° C. asdetermined in accordance with ASTM Method D5307.
 8. The process of claim1 further comprising the steps of: continuously or intermittentlyproviding hydrogen sulfide to the mixing zone and blending the hydrogensulfide with the hydrocarbon-containing feedstock, the catalyst, andhydrogen in the mixing zone, wherein hydrogen sulfide is provided to themixing zone at a mole ratio of hydrogen sulfide to hydrogen of at least0.5:9.5 up to 1:1, where hydrogen and hydrogen sulfide are provided formixing such that the combined hydrogen and hydrogen sulfide partialpressures provide at least 60% of the total pressure.
 9. The process ofclaim 1 wherein the hydrocarbon-containing feedstock contains at least30 wt. % of hydrocarbons having a boiling point of greater than 538° C.as determined in accordance with ASTM Method D5307.
 10. The process ofclaim 1 wherein the hydrocarbon-containing feedstock contains at least30 wt. % of hydrocarbons that have a boiling point of 538° C. or less asdetermined in accordance with ASTM Method D5307.
 11. The process ofclaim 2 wherein the hydrocarbon-containing product condensed from thevapor separated from the mixing zone contains at least 40% of the atomicsulfur present in the hydrocarbon-containing feedstock.
 12. The processof claim 1 wherein the hydrocarbon-containing product condensed from thevapor separated from the mixing zone contains at least 40% of the atomicnitrogen present in the hydrocarbon-containing feedstock.
 13. Theprocess of claim 1 wherein the catalyst provided to mixing zone has anacidity as measured by ammonia chemisorption of at most 200 μmol ammoniaper gram of catalyst.
 14. The process of claim 13 wherein at least onecatalyst provided to the mixing zone and blended with thehydrocarbon-containing feedstock and hydrogen comprises a metal ofColumns 6-10 of the Periodic Table or a compound of a metal of Columns6-10 of the Periodic Table.
 15. The process of claim 13 wherein at leastone catalyst comprises a metal of Column 6, 14, or 15 of the PeriodicTable or a compound of a metal of Column 6, 14, or 15 of the PeriodicTable and a metal of Column(s) 3 or 7-15 of the Periodic Table or acompound of a metal of Column(s) 3 or 7-15 of the Periodic Table. 16.The process of claim 1 wherein the catalyst comprises a materialcomprised of a first metal and a second metal where the first metalcomprises a metal selected from the group consisting of Cu, Ni, Co, Fe,Ag, Mn, Zn, Sn, Ru, La, Ce, Pr, Sm, Eu, Yb, Lu, Dy, Pb, Sb, and Bi,where the second metal comprises a metal selected from the groupconsisting of Mo, W, V, Sn, and Sb, where the second metal is not thesame as the first metal, and wherein the material is comprised of atleast three linked chain elements, the chain elements comprising a firstchain element including the first metal and having a structure accordingto formula (I) and a second chain element including the second metal andhaving a structure according to formula (II)

where at least one chain element in the material is a first chainelement and at least one chain element in the material is a second chainelement, where chain elements in the material are linked by bondsbetween the two sulfur atoms of a chain element and the metal of anadjacent chain element.
 17. The process of claim 1 wherein the catalystis comprised of a material comprised of a first metal and a second metalwhere the first metal comprises a metal selected from the groupconsisting of Cu, Ni, Co, Fe, Ag, Mn, Zn, Sn, Ru, La, Ce, Pr, Sm, Eu,Yb, Lu, Dy, Pb, Sb, and Bi where the second metal comprises a metalselected from the group consisting of Mo, W, V, Sn and Sb, where thesecond metal is not the same as the first metal, and wherein at least aportion of the material of the catalyst has a structure according to aformula selected from the group consisting of formula (III), formula(IV), formula (V), and formula (VI):

where M is either the first metal or the second metal, and at least oneM is the first metal and at least one M is the second metal;

where M is either the first metal or the second metal, at least one M isthe first metal and at least one M is the second metal, and X isselected from the group consisting of SO₄, PO₄, oxalate (C₂O₄),acetylacetonate, acetate, citrate, tartrate, Cl, Br, I, ClO₄, and NO₃;

where M is either the first metal or the second metal, at least one M isthe first metal and at least one M is the second metal, and X isselected from the group consisting of SO₄, PO₄, oxalate (C₂O₄),acetylacetonate, acetate, citrate, tartrate, Cl, Br, I, ClO₄, and NO₃;

where M is either the first metal or the second metal, at least one M isthe first metal and at least one M is the second metal, and X isselected from the group consisting of SO₄, PO₄, oxalate (C₂O₄),acetylacetonate, acetate, citrate, tartrate, Cl, Br, I, ClO₄, and NO₃.18. The process of claim 1 wherein at least one catalyst is a solidparticulate material having a particle size distribution having a medianparticle size or a mean particle size of from 50 nm to 1 μm.
 19. Theprocess of claim 1 wherein the temperature in the mixing zone isselected and controlled to be at least 430° C.
 20. The process of claim1 wherein the hydrocarbon-containing product contains at most 0.001 wt.% vanadium and at most 0.001 wt. % nickel.
 21. The process of claim 1wherein the hydrocarbon-depleted feed residuum contains less than 0.02grams of substances insoluble in toluene as determined in accordancewith ASTM Method D4072, excluding the catalyst(s), per gram ofhydrocarbon-containing feedstock provided to the mixing zone.
 22. Theprocess of claim 1 further comprising the steps of: separating a streamcontaining liquids and solids from the mixing zone; separating solidsfrom the stream containing liquids and solids to produce a liquid streamand a solid material; and providing the liquid stream to the mixingzone.
 23. A process for cracking a hydrocarbon-containing feedstock,comprising: providing a hydrocarbon-containing feedstock to a mixingzone, where the hydrocarbon-containing feedstock is selected to containat least 20 wt. % residue; providing at least one catalyst to the mixingzone; continuously or intermittently providing hydrogen to the mixingzone and blending the hydrogen, the hydrocarbon-containing feedstock,and the catalyst in the mixing zone at a temperature of from 375° C. to500° C. and at a pressure of from 3.4 MPa to 27.5 MPa to produce: a) avapor comprised of hydrocarbons that are vaporizable at the temperatureand the pressure within the mixing zone; and b) a hydrocarbon-depletedfeed residuum comprising hydrocarbons that are liquid at the temperatureand the pressure within the mixing zone; continuously or intermittentlyseparating at least a portion of the vapor from the mixing zone whileretaining in the mixing zone at least a portion of thehydrocarbon-depleted feed residuum comprising hydrocarbons that areliquid at the temperature and pressure within the mixing zone; apartfrom the mixing zone, condensing a liquid hydrocarbon-containing productthat contains at least 90% of the atomic carbon initially contained inthe hydrocarbon-containing feedstock and that contains less than 2 wt. %hydrocarbons having a boiling point of at least 538° C. as determined inaccordance with ASTM Method D5307 from at least a portion of the vaporseparated from the mixing zone.